Aaaa
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monitor interface Syntax
monitor interface Description
Display real-time statistics about a physical interface, updating them every second. The output of this command also shows the amount that each field has changed since you started the command or since you cleared the counters by using the c key. This command also checks for and displays common interface failures, such as SDH/SONET and T3 alarms, loopbacks detected, and increases in framing errors. To control the output of the command while it is running, use the following keys: Action
Key
Display information about the next physical interface. The monitor interface n command scrolls through the interfaces in the same order that they are displayed by the show interfaces terse command. Display information about a different interface. The command prompts you for the name of a specific physical interface.
i
Freeze the display, halting the display of updated statistics.
f
Thaw the display, resuming the display of updated statistics.
t
Clear (zero) the counters.
c
Stop the monitor interface command.
q
Options
interface-name--Name of a physical interface. traffic--Display traffic data for active interfaces Required Privilege Level
trace See Also
show interfaces statistics, show interfaces statistics. Sample Output user@host> monitor interface so-0/0/0 router1 Seconds: 19 15:46:29 Interface: so-0/0/0, Enabled, Link is Up Encapsulation: PPP, Keepalives, Speed: OC48 Traffic statistics: Delta Input packets: 6045 (0 [11] Input bytes: 6290065 (0 [13882] Output packets: 10376 (0 [10] Output bytes: 10365540 (0 [9418] Encapsulation statistics: Input keepalives: 1901 [2] Output keepalives: 1901 [2] NCP state: Opened LCP state: Opened Error statistics: Input errors: 0 [0] Input drops: 0 [0] Input framing errors: 0 [0] Policed discards: 0 [0] L3 incompletes: 0 [0] L2 channel errors: 0 [0] L2 mismatch timeouts: 0 [0] Carrier transitions: 1 [0] Output errors: 0 [0] Output drops: 0 [0] Aged packets: 0 [0] Active alarms : None Active defects: None SONET error counts/seconds: LOS count 1 [0]
Time:
Current pps) bps) pps) bps)
LOF count
1
SEF count
1
ES-S
0
[0] [0] [0]
SES-S [0] SONET statistics: BIP-B1 [0] BIP-B2 [0] REI-L [0] BIP-B3 [0] REI-P [0] Received SONET overhead: F1 : 0x00 J0 K2 : 0x00 S1 C2(cmp) : 0x00 F2 Z4 : 0x00 S1(cmp) Transmitted SONET overhead: F1 : 0x00 J0 K2 : 0x00 S1 F2 : 0x00 Z3
0 458871 460072 465610 458978 458773 : : : :
0x00 0x00 0x00 0x00
K1 C2 Z3
: 0x00 : 0x00 : 0x00
: 0x01 : 0x00 : 0x00
K1 C2 Z4
: 0x00 : 0xcf : 0x00
Next='n', Quit='q' or ESC, Freeze='f', Thaw='t', Clear='c', Interface='i' user@host> monitor interface traffic host name Seconds: 6 Interface (pps) at-0/2/0 (0) at-0/3/0 (0) so-1/0/0 (0) ge-1/1/0 (0) ge-1/1/1 (0) so-2/0/0:0 (0) so-2/0/0:1 (0) so-2/0/0:2 (0) so-2/0/0:3 (0) t1-3/2/0:0 (0)
Time: 16:17:19
Input packets
(pps)
Output packets
0
(0)
0
0
(0)
0
0
(0)
0
0
(0)
0
0
(0)
0
0
(0)
0
0
(0)
0
0
(0)
0
0
(0)
0
0
(0)
0
t1-3/2/0:10 (0) t1-3/2/0:11 (0) t1-3/2/0:12 (0) t1-3/2/0:13 (0) t1-3/2/0:14 (0) t1-3/2/0:15 (0) t1-3/2/0:16 (0) t1-3/2/0:17 (0)
0
(0)
0
0
(0)
0
0
(0)
0
0
(0)
0
0
(0)
0
0
(0)
0
0
(0)
0
0
(0)
0
Next='n', Quit='q' or ESC, Freeze='f', Thaw='t', Clear='c', Interface='i'
Output Fields
router1--Host name of the router. Seconds--How long the monitor interface command has been running or how long since you last zeroed the counters. Time--Current time (UTC). Interface--Short description of the interface, including its name, status, and encapsulation. Current delta--Cumulative number for the counter in question since the time shown in the Seconds field, which is the time since you started the command or last zeroed the counters. Statistics--For an explanation of the interface statistics, see the description of the show interfaces statistics detail command for the appropriate interface type.
.: Monitors :. Resolution Imagine lying down in the grass with your nose pressed deep into the thatch. Your field of vision would not be very large, and all you would see are a few big blades of grass, some grains of dirt, and maybe an ant or two. This is a 14-inch 640 x 480 monitor. Now, get up on your hands and knees, and your field of vision will improve considerably: you'll see a lot more grass. This is a 15-inch 800 x 640 monitor. For a 1280 x 1024 perspective (on a 19-inch monitor), stand up and look
at the ground. Some monitors can handle higher resolutions such as 1600 x 1200 or even 1920 x 1440—somewhat akin to a view from up in a tree. Monitors are measured in inches, diagonally from side to side (on the screen). However, there can be a big difference between that measurement and the actual viewable area. A 14-inch monitor only has a 13.2-inch viewable area, a 15-inch sees only 13.8 inches, and a 20-inch will give you 18.8 inches (viewing 85.7% more than a 15-inch screen). A computer monitor is made of pixels (short for "picture element"). Monitor resolution is measured in pixels, width by height. 640 x 480 resolution means that the screen is 640 pixels wide by 480 tall, an aspect ratio of 4:3. With the exception of one resolution combination (1280 x 1024 uses a ratio of 5:4), all aspect ratios are the same. From The PC Guide, by Charles M. Kozierok: A pixel is the smallest element of a video image, but not the smallest element of a monitor's screen. Since each pixel must be made up of three separate colors, there are smaller red, green, and blue dots on the screen that make up the image. The term dot is used to refer to these small elements that make up the displayed image on the screen. In order to use different resolutions on a monitor, the monitor must be able to support automatic changing of resolution modes. Originally, monitors were fixed at a particular resolution, but most monitors today are capable of changing their displayed resolution under software control. This allows for higher or lower resolution depending on the needs of the application. A higher resolution display shows more on the screen at one time, and the maximum resolution that a monitor can display is limited by the size of the monitor and the characteristics of the CRT (cathode-ray tube). In addition, the monitor must have sufficient input bandwidth to allow for refresh of the screen, which becomes more difficult at higher resolutions because there is so much more information being sent to the monitor. You can see by the chart below how screen size and effective resolution are linked. Compare a 15-inch monitor and a 21-inch monitor, both set to 800 x 600 pixels: the 15-inch will have a higher resolution. Larger monitors must contain smaller pixels in order to maintain the same resolution, but when a smaller monitor is set to a high resolution, the images would be much too small to read. A 14-inch monitor set to 640 x 480 is very readable, while a 21-inch needs at least 1024 x 768. Here are some recommended resolutions for the different screen sizes: 14"
15"
17"
19"
21"
640x480
BEST
GOOD
TOO BIG
HUGE
TERRIBLE
800x600
GOOD
BEST
GOOD
TOO BIG
HUGE
1024x768
TOO SMALL
GOOD
BEST
GOOD
STILL GOOD
1280x1024
TINY
TOO SMALL
GOOD
BEST
GOOD
1600x1200
TERRIBLE
TINY
TOO SMALL
GOOD
BEST
TheScreamOnline is optimized for viewing at 1024 x 768 resolution. As you can see by the chart above, it should look good on most monitors. Be aware that there are many versions and interpretations of these settings. This table is an average of various opinions.
Adjusting Resolution On a PC with Windows, do the following: 1. Double-click the Display Icon in the Control Panel by clicking: Start > Settings > Control Panel. 2. Select the "Settings" tab in the Display Properties Dialog Box. 3. Adjust the slider to 800 x 600 (shown below), then click the Test Button. A test bitmap will appear for 5 seconds, then you will be asked if everything looked OK. Click YES to confirm.
On a Mac, go to Control Panels > Monitors and you will see a list of settings. It couldn't be easier.
Color From The PC Guide, by Charles M. Kozierok There are 4 standard color depths used by monitors: 4-bit (Standard VGA), 8-bit (256-Color Mode), 16-bit (High Color),and 24-bit (True Color). Each pixel of the screen image is displayed using a combination of three different color signals: red, green, and blue. The appearance of each pixel is controlled by the intensity of these three beams of light. When all are set to the highest level the result is white; when all are set to zero the pixel is black. The amount of information that is stored about a pixel determines its color depth, which controls how precisely the pixel's color can be specified. This is also sometimes called the bit depth, because the precision of color depth is specified in bits. The more bits that are used per pixel, the finer the color detail of the image. However, increased color depths also require significantly more memory for storage of the image, and also more data for the video card to process, which reduces the possible maximum refresh rate. [Computers use a binary language of two numbers, "one" and" zero," signifying "on" and "off." Bit depth is the number of bits in each pixel. Color depth is the maximum number of colors in an image and is based on the bit depth of the image and of the displaying monitor. A black and white monitor uses 1-bit color depth (2 to the power of 1): black=light off, and white= light on. Each pixel has a bit depth of one and a color depth of two. One bit produces two possible colors. Color monitors use at least 2-bit color, or 2-to-the-2nd power (2x2=4), meaning that 4 shades of color are available for each of the three primary colors (red, blue, and green). 4-bit color (2x2x2x2=16) means that each of the primaries has 16 shades; the greater the bit depth, the more shades for each color. See the chart below for a comparison of bit depth and color resolution. —Ed.] 256-Color Mode: uses only 8 bits (2 bits for blue, 3 for green, 3 for red). Choosing between only 4 or 8 different values for each color would result in poor blocky color, so a different approach is taken instead: the use of a palette. A palette is
created containing 256 different colors. Each one is defined using the standard 3byte color definition that is used in true color: 256 possible intensities for each of red, blue, and green. Each pixel is allowed to choose one of the 256 colors in the palette, which can be considered a "color number" of sorts. So the full range of color can be used in each image, but each image can only use 256 of the available 16 million different colors. When each pixel is displayed, the video card looks up the real RGB values in the palette based on the "color number" the pixel is assigned. The palette approach is an excellent compromise: it allows only 8 bits to be used to specify each color in an image, but allows the creator of the image to decide what the 256 colors in the image should be. Since virtually no images contain an even distribution of colors, this allows for more precision in an image by using more colors than would be possible by assigning each pixel a 2-bit value for blue and 3-bit values each for green and red. For example, an image of the sky with clouds would have many different shades of blue, white, and gray, and virtually no reds, greens, or yellows. 256-color is the standard for much of computing, mainly because the higherprecision color modes require more resources (especially video memory) and aren't supported by many PC's. Despite the ability to "hand pick" the 256 colors, this mode produces noticeably worse image quality than high color, and most people can tell the difference between high color and 256-color mode. High color: 16-bit color—uses two bytes of information to store the intensity values for the three colors. This is done by breaking the 16 bits into 5 bits for blue, 5 bits for red, and 6 bits for green, giving 32 different intensities for blue, 32 for red, and 64 for green. This reduced color precision results in a slight loss of visible image quality, but it is actually very slight—most people cannot see the differences between true color and high color images unless they are looking for them. For this reason high color is often used instead of true color—it requires 33% (or 50% in some cases) less video memory, and it is also faster for the same reason. True color: 24-bit color—three bytes of information are used, one for each of the red, blue, and green signals that make up each pixel. Since a byte has 256 different values, each color can have 256 different intensities, using over 16 million different color possibilities, and allowing for a very realistic representation of the color of images, with no compromises necessary and no restrictions on the number of colors an image can contain. In fact, 16 million colors is more than the human eye can discern, though true color is necessary for doing high-quality photo editing, graphic design, etc. [Some video cards have to use 32 bits of memory for each pixel when operating in true color, due to how they use the video memory.] [TheScreamOnline is best viewed with 24-bit color, or millions of colors, though thousands of colors will suffice. On a Mac, go to Control Panels > Monitors (see
graphic above under Adjusting Resolution) and set the color depth to thousands or millions of colors if your video card supports it. Lowering the resolution of your screen display may allow you to achieve a greater color depth. On a Windows computer, go to Start Menu > Settings > Control Panels > Display > Settings. —Ed.] BIT DEPTH
COLOR RESOLUTION
CALCULATION
1-bit
2 colors
2 (2)
2-bit
4 colors
2 (2x2)
3-bit
8 colors
2 (2x2x2)
4-bit
16 colors
2 (2x2x2x2)
5-bit
32 colors
2 (2x2x2x2x2)
6-bit
64 colors
2 (2x2x2x2x2x2)
7-bit
128 colors
2 (2x2x2x2x2x2x2)
8-bit
256 colors
2 (2x2x2x2x2x2x2x2)
16-bit
65,536 colors
2
24-bit
16,777,215 colors
2
Monitors vs. Browsers Four variables tend to make the life of a web designer a living hell. Macintosh monitors display text at 72 dpi (dots-per-inch) and PC's take 96 pixels to show that same text. Translation: a PC monitor enlarges the type—sort of like reading a large-print novel. Differences in the two major browsers (Netscape and Internet Explorer) also add to the problem. Netscape is close to WYSIWYG (What You See Is What You Get)—it doesn't significantly change how a webpage is meant to appear. Internet Explorer (or IE), on the other hand, enlarges text one-to-two point sizes. So, a page of text can appear four different ways, depending on the combination: Netscape on a Mac, IE on a Mac, Netscape on a PC, and IE on a PC. The difference between viewing a page on a Mac using the Netscape browser and that same page on a PC with IE is enormous. A lot of seemingly unnecessary time is spent by web designers trying to "dumbdown" a site so that it looks acceptable in all formats. Many designers, however, say "To hell with those with cheap equipment," and create a site for users with high-end gear. If only the two platforms and browsers could conform to a standard, then most of these woes wouldn't exist and not only could designers focus more on the quality of the design itself, the product would be better and the end-user (you!) would consistently see websites as they were meant to be viewed.
Caveat Emptor Many of the low-price "deals" that come with PC packages can include—in addition to the requisite monitor, CPU, and keyboard—a modem, scanner, Zip drive, printer, and CD-rom drive. Be careful—you get what you pay for. Much of the time you will end up with a very inexpensive 8-bit 640 x 480 monitor that cannot be adjusted. While a good monitor (large size with a high resolution/bandwidth/refresh rate and small dot pitch) will hold its value for some time, CPU's will be worth only a fraction of their original cost after about a year. If you just use a computer for basic word-processing and email communications, then the cheap route is probably adequate. Beyond that, you will quickly realize the limitations of your purchase. If you are serious about creating, or at least viewing, high-quality images, in addition to viewing websites as they are meant to be seen, then it would be wise to invest in the appropriate equipment.
Interface Monitor Overview
The Interface Monitor Plugin gives you a detail and synthetic view of a network interface status. The use of the MIB II standard allows you to get this information of almost all system and network devices. The % of the current load is diplayed in a line graph and tells you in a blink of one eye if your interface is overloaded. You can specify a pourcentage of load (threshold) that will generate an alarm if this one is reached.
Installation The installation of the Interface Monitor Plugin is performed in the directory workspace. Select one host in your directory and then from the contextual Menu select Insert Task and Plugin.
You should see the following result in your workspace.
By a double click on the hammer icon you should start the Plugin Dialog Window and could configure it.
Configuration The configuration of the Interface Monitor is performed directly in the Plugin main window. Few parameter have to be set. You should first select an interface frome the list.
You should set a polling interval. If the polling interval is high the line graph x scale will be bigger and thus you will have a view on a longer time period.
If you want to be warn when a load threshold is reached you have to set up the three fields.
"If usage >" parameter specifies the load threshold in % above which you want to be warn. "Send Event" parameter should contain the event number displayed in the event manager (value should be unique within your set of events and higher than 10000). The "At level" value (between 0 and 10) specifies the gravity of the alarm and the color of the event. The screen below shows you example of alarm for each severity level.
Supervision The information provided by the various indicators present in the screen are all very instructive and give rich information on the interface traffics and errors. Here is the list of these indicators. Graph : Incoming/Outgoing for interface index ... Graph : Interface load in % Graph : Packets in Error Graph : Packets Discarded Information ifAdminStatus (Interface Administrative Status) ifinUnknowProtos (Interface Inbound unknow Protocol) ifinUcastPkts (Interface Inbound Unicast Packets) ifinNUcastPkts (Interface Inbound Non-Unicast packets) ifOperStatus (Interface Operational Status) ifOutQlen (Interface Output Queue lenght) ifOutUcastPkts (Interface Out Unicast packets) ifOutNUcastPkts (Interface Out Non-unicast Packets) Broadcast and Multicast Rx discard Pkts/s (Received Packets discarded) Tx discard Pkts/s Rx error Pkts/s Tx error Pkts/s Rx broad Pkts/s Tx broad Pkts/s
Graph : Incoming/Outgoing for interface index ... This graph displays the number of octets sent and received by the interface. The in (yellow) line display the incoming octet value, the out (purple) line displays the ougoing octet value. Both value comes from the ifOutOctets OID (The total number of octets transmitted out of the interface, including framing characters) and ifInOctects OID (The total number of octets received on the interface, including framing characters.
The y-axis displays octet values, the x-axis is the time scale. The value displayed on the y-axis is the number of inbound or ounbond Octets counted during the polling interval. The octet value depends from the polling interval selection. if you want to know the octet/second values you should do the following conversion. y-axis value / Polling interval = Octets per second (average) If you want to have a speed value in bits per second the formula is : (y-axis value / Polling interval) * 8 = Bits per second (average) With this formula, remenber that more the polling interval is high more the value is averaged. In other words, if your traffic contains surges you could miss them. The following table gives you examples of values for various interface types, various polling intervals and various loads.
Number of octets per polling interval Interface type Load
Interface Speed Mbps
1 seconds 5 secondes 8 seconds
10 seconds
30 seconds
60 seconds
5 mn
4 000 octets/s 50 % load on LL 64 Kbps
64 000
4 000
20 000
32 000
40 000
120 000
240 000
1 200 000
8 000 octets/s 100 % load 64 000 on LL 64 Kpbs
8 000
40 000
64 000
80 000
240 000
480 000
2 400 000
125 000 octets/s 50 % load on E1 line
125 000
625 000
1 000 000
1 250 000
3 750 000
7 500 000
37 500 000
2 000 000
250 000 octets/s 2 000 000 100 % load on E1 line
250 000
1 250 000
2 000 000
2 500 000
7 500 000
15 000 000
75 000 000
625 000 octets/s = 50% load 10 000 000 625 000 on Ethernet 100 Mbps
3 125 000
5 000 000
6 250 000
18 750 000
37 500 000
187 500 000
1 250 000 octets/s = 100% load on Ethernet 100 Mbps
1 250 000
6 250 000
10 000 000
12 500 000
37 500 000
75 000 000
375 000 000
6 250 000 octets/s 100 000 = 50% load 000 on Ethernet 100 Mbps
6 250 000
31 250 000
50 000 000
62 500 000
187 500 000
375 000 000
1 875 000 000
12 500 000 octets/s = 100% 100 000 load on 000 Ethernet 100 Mbps
12 500 000
62 500 000
100 000 000
125 000 000
375 000 000
750 000 000
3 750 000 000
10 000 000
Graph : Interface load in %
This graph displays the percentage of load for the interface. Two lines, one for the incoming traffic, one for the outgoing traffic are represented.
The -
reading
%
the
of interface
load speed
is value
in
calculated Bits/s
by (ifSpeed
: OID)
- reading the current throughput in - and by applying the following formula :
Octets/s
(ifIinOctets
and
ifOutOctets
OIDs)
(Octets per second / Polling interval) / ((Speed of interface in Bits per second) / 8 / 100 ) The maximum reached by one of both indicator is displayed as a white line and its value is indicated on the right side (82.10 % for the Inbound load in our example).
Graph : Packets in Error Error packet are malformed packet at the link control layer, Ethernet for example, that could not be used by upper applications. The maximum reached by one of both indicators is displayed as a white line and its value is indicated on the right side.
The value displayed on the y-axis is the number of inbound or outbound packets counted during the polling interval. This table gives you the value in Pkts/s and their corresponding values for various polling interval .
Number of packets per polling interval 1 seconds 5 secondes 8 seconds 10 seconds 30 seconds 60 seconds 5 mn 10 Pkts/s
10
50
80
100
300
600
3000
100 Pkts/
100
500
800
1 000
3 000
6 000
30 000
1 000 Pkts/s
1 000
5 000
8 000
10 000
30 000
60 000
300 000
10 000 Pkts/s
10 000
50 000
80 000
100 000
300 000
600 000
3 000 000
In our screen shot the maximum value recorded is 5817 packets. It gives us an average of 1164 Packet per second.
Graph : Packets Discarded The graph displays the number of inbound and outbound packets which were chosen to be discarded even though no errors had been detected to prevent their being deliverable to a higher-layer protocol. One possible reason for discarding such a packet could be to free up buffer space. The maximum reached by one of both indicator is displayed as a white line and its value is indicated on the right side.
The value displayed on the y-axis is the number of inbound or outbound packets counted during the polling interval.
Information This
field
displays
information
about
the
Network
interface.
Description. The name given to the interface for better identification Type. The type of interface, distinguished according to the physical/link protocol(s) immediately below the network layer in the protocol stack. MTU (maximum Transmit Unit). The size of the largest datagram which can be sent/received on the interface, specified in octets. For interfaces that are used for transmitting network datagrams, this is the size of the largest network datagram that can be sent on the interface. Speed. An estimate of the interface's current bandwidth in bits per second. For interfaces which do not vary in bandwidth or for those where no accurate estimation can be made, this object should contain the nominal bandwidth. Physical address. The interface's address at the protocol layer immediately `below' the network layer in the protocol stack. For interfaces which do not have such an address (e.g., a serial line), this object should contain an octet string of zero length.
ifAdminStatus - Interface Administrative Status
The desired state of the interface. The states could be :
• • •
up(1) ready to send or receive packets down(2) unable to send or receive packets testing(3) in some test mode
The testing(3) state indicates that no operational packets can be passed.
ifinUnknowProtos - Interface Inbound Unknown Protocols The number of packets received via the interface which were discarded because of an unknown or unsupported protocol. Accepted protocols should be supported by the type of interface. ifinUcastPakts - Interface Inbound Unicast Packets The
number
of
subnetwork-unicast
packets
delivered
to
a
higher-layer
protocol.
ifinNUcastPkts - Interface Inbound Non-Unicast Packets (Broadcast and Multicast) The number of non-unicast (i.e., subnetwork- broadcast or subnetwork-multicast) packets delivered to a higher-layer protocol. ifOperStatus - Interface Operational Status The current operational state of the interface.
• • • The packets
up(1) ready to send or receive packets down(2) unable to send or receive packets testing(3) in some test mode
testing(3)
state can
indicates
that be
no
operational passed.
ifOutQlen - Interface Output Queue Lenght The
length
of
the
output
packet
queue
(in
packets)
ifOutUcastPkts - Interface Outbound Unicast Packets The total number of packets that higher-level protocols requested be transmitted to a subnetwork-unicast address, including those that were discarded or not sent. ifOutNUcastPkts - Interface Outbound Non-Unicast Packets The total number of packets that higher-level protocols requested be transmitted to a nonunicast (i.e., a subnetwork-broadcast or subnetwork-multicast) address, including those that were discarded or not sent.
Rx discard Pkts/s
The average value of received packets discarded per second during the polling interval Tx discard Pkts/s The average value of transmitted packets in error per second during the polling interval Rx error Pkts/s The average value of received packets in error per second during the polling interval Tx error Pkts/s The average value of transmitted packets in error per second during the polling interval Rx broad Pkts/s The average value of broadcast packet received per second during the polling interval Tx broad Pkts/s The average value of broadacst packet transmitted per second during the polling interval
monitor interface
Display real-time statistics about a physical interface, updating them every second. The output of this command also shows the amount that each field has changed since you started the command or since you cleared the counters by using the c key. This command also checks for and displays common interface failures, such as SDH/SONET and T3 alarms, loopbacks detected, and increases in framing errors. To control the output of the command while it is running, use the following keys: Action
Key
Display information about the next physical interface. The monitor interface n command scrolls through the interfaces in the same order that they are displayed by the show interfaces terse command. Display information about a different interface. The command prompts you for the name of a specific physical interface.
i
Freeze the display, halting the display of updated statistics.
f
Thaw the display, resuming the display of updated statistics.
t
Clear (zero) the counters.
c
Stop the monitor interface command.
q
Options
interface-name--Name of a physical interface. traffic--Display traffic data for active interfaces Required Privilege Level
trace See Also
show interfaces statistics, show interfaces statistics. Sample Output user@host> monitor interface so-0/0/0 router1 Seconds: 19 15:46:29 Interface: so-0/0/0, Enabled, Link is Up Encapsulation: PPP, Keepalives, Speed: OC48 Traffic statistics: Delta Input packets: 6045 (0 [11] Input bytes: 6290065 (0 [13882] Output packets: 10376 (0 [10] Output bytes: 10365540 (0 [9418] Encapsulation statistics: Input keepalives: 1901 [2] Output keepalives: 1901 [2] NCP state: Opened LCP state: Opened Error statistics: Input errors: 0 [0] Input drops: 0 [0] Input framing errors: 0 [0] Policed discards: 0 [0] L3 incompletes: 0 [0] L2 channel errors: 0 [0] L2 mismatch timeouts: 0 [0] Carrier transitions: 1 [0] Output errors: 0 [0] Output drops: 0 [0] Aged packets: 0 [0] Active alarms : None Active defects: None SONET error counts/seconds: LOS count 1 [0]
Time:
Current pps) bps) pps) bps)
LOF count
1
SEF count
1
ES-S
0
[0] [0] [0]
SES-S [0] SONET statistics: BIP-B1 [0] BIP-B2 [0] REI-L [0] BIP-B3 [0] REI-P [0] Received SONET overhead: F1 : 0x00 J0 K2 : 0x00 S1 C2(cmp) : 0x00 F2 Z4 : 0x00 S1(cmp) Transmitted SONET overhead: F1 : 0x00 J0 K2 : 0x00 S1 F2 : 0x00 Z3
0 458871 460072 465610 458978 458773 : : : :
0x00 0x00 0x00 0x00
K1 C2 Z3
: 0x00 : 0x00 : 0x00
: 0x01 : 0x00 : 0x00
K1 C2 Z4
: 0x00 : 0xcf : 0x00
Next='n', Quit='q' or ESC, Freeze='f', Thaw='t', Clear='c', Interface='i' user@host> monitor interface traffic host name Seconds: 6 Interface (pps) at-0/2/0 (0) at-0/3/0 (0) so-1/0/0 (0) ge-1/1/0 (0) ge-1/1/1 (0) so-2/0/0:0 (0) so-2/0/0:1 (0) so-2/0/0:2 (0) so-2/0/0:3 (0) t1-3/2/0:0 (0)
Time: 16:17:19
Input packets
(pps)
Output packets
0
(0)
0
0
(0)
0
0
(0)
0
0
(0)
0
0
(0)
0
0
(0)
0
0
(0)
0
0
(0)
0
0
(0)
0
0
(0)
0
t1-3/2/0:10 (0) t1-3/2/0:11 (0) t1-3/2/0:12 (0) t1-3/2/0:13 (0) t1-3/2/0:14 (0) t1-3/2/0:15 (0) t1-3/2/0:16 (0) t1-3/2/0:17 (0)
0
(0)
0
0
(0)
0
0
(0)
0
0
(0)
0
0
(0)
0
0
(0)
0
0
(0)
0
0
(0)
0
Next='n', Quit='q' or ESC, Freeze='f', Thaw='t', Clear='c', Interface='i'
Output Fields
router1--Host name of the router. Seconds--How long the monitor interface command has been running or how long since you last zeroed the counters. Time--Current time (UTC). Interface--Short description of the interface, including its name, status, and encapsulation. Current delta--Cumulative number for the counter in question since the time shown in the Seconds field, which is the time since you started the command or last zeroed the counters. Statistics--For an explanation of the interface statistics, see the description of the show interfaces statistics detail command for the appropriate interface type.
.: Monitors :. Resolution Imagine lying down in the grass with your nose pressed deep into the thatch. Your field of vision would not be very large, and all you would see are a few big blades of grass, some grains of dirt, and maybe an ant or two. This is a 14-inch 640 x 480 monitor. Now, get up on your hands and knees, and your field of vision will improve considerably: you'll see a lot more grass. This is a 15-inch 800 x 640 monitor. For a 1280 x 1024 perspective (on a 19-inch monitor), stand up and look
at the ground. Some monitors can handle higher resolutions such as 1600 x 1200 or even 1920 x 1440—somewhat akin to a view from up in a tree. Monitors are measured in inches, diagonally from side to side (on the screen). However, there can be a big difference between that measurement and the actual viewable area. A 14-inch monitor only has a 13.2-inch viewable area, a 15-inch sees only 13.8 inches, and a 20-inch will give you 18.8 inches (viewing 85.7% more than a 15-inch screen). A computer monitor is made of pixels (short for "picture element"). Monitor resolution is measured in pixels, width by height. 640 x 480 resolution means that the screen is 640 pixels wide by 480 tall, an aspect ratio of 4:3. With the exception of one resolution combination (1280 x 1024 uses a ratio of 5:4), all aspect ratios are the same. From The PC Guide, by Charles M. Kozierok: A pixel is the smallest element of a video image, but not the smallest element of a monitor's screen. Since each pixel must be made up of three separate colors, there are smaller red, green, and blue dots on the screen that make up the image. The term dot is used to refer to these small elements that make up the displayed image on the screen. In order to use different resolutions on a monitor, the monitor must be able to support automatic changing of resolution modes. Originally, monitors were fixed at a particular resolution, but most monitors today are capable of changing their displayed resolution under software control. This allows for higher or lower resolution depending on the needs of the application. A higher resolution display shows more on the screen at one time, and the maximum resolution that a monitor can display is limited by the size of the monitor and the characteristics of the CRT (cathode-ray tube). In addition, the monitor must have sufficient input bandwidth to allow for refresh of the screen, which becomes more difficult at higher resolutions because there is so much more information being sent to the monitor. You can see by the chart below how screen size and effective resolution are linked. Compare a 15-inch monitor and a 21-inch monitor, both set to 800 x 600 pixels: the 15-inch will have a higher resolution. Larger monitors must contain smaller pixels in order to maintain the same resolution, but when a smaller monitor is set to a high resolution, the images would be much too small to read. A 14-inch monitor set to 640 x 480 is very readable, while a 21-inch needs at least 1024 x 768. Here are some recommended resolutions for the different screen sizes: 14"
15"
17"
19"
21"
640x480
BEST
GOOD
TOO BIG
HUGE
TERRIBLE
800x600
GOOD
BEST
GOOD
TOO BIG
HUGE
1024x768
TOO SMALL
GOOD
BEST
GOOD
STILL GOOD
1280x1024
TINY
TOO SMALL
GOOD
BEST
GOOD
1600x1200
TERRIBLE
TINY
TOO SMALL
GOOD
BEST
TheScreamOnline is optimized for viewing at 1024 x 768 resolution. As you can see by the chart above, it should look good on most monitors. Be aware that there are many versions and interpretations of these settings. This table is an average of various opinions.
Adjusting Resolution On a PC with Windows, do the following: 1. Double-click the Display Icon in the Control Panel by clicking: Start > Settings > Control Panel. 2. Select the "Settings" tab in the Display Properties Dialog Box. 3. Adjust the slider to 800 x 600 (shown below), then click the Test Button. A test bitmap will appear for 5 seconds, then you will be asked if everything looked OK. Click YES to confirm.
On a Mac, go to Control Panels > Monitors and you will see a list of settings. It couldn't be easier.
Color From The PC Guide, by Charles M. Kozierok There are 4 standard color depths used by monitors: 4-bit (Standard VGA), 8-bit (256-Color Mode), 16-bit (High Color),and 24-bit (True Color). Each pixel of the screen image is displayed using a combination of three different color signals: red, green, and blue. The appearance of each pixel is controlled by the intensity of these three beams of light. When all are set to the highest level the result is white; when all are set to zero the pixel is black. The amount of information that is stored about a pixel determines its color depth, which controls how precisely the pixel's color can be specified. This is also sometimes called the bit depth, because the precision of color depth is specified in bits. The more bits that are used per pixel, the finer the color detail of the image. However, increased color depths also require significantly more memory for storage of the image, and also more data for the video card to process, which reduces the possible maximum refresh rate. [Computers use a binary language of two numbers, "one" and" zero," signifying "on" and "off." Bit depth is the number of bits in each pixel. Color depth is the maximum number of colors in an image and is based on the bit depth of the image and of the displaying monitor. A black and white monitor uses 1-bit color depth (2 to the power of 1): black=light off, and white= light on. Each pixel has a bit depth of one and a color depth of two. One bit produces two possible colors. Color monitors use at least 2-bit color, or 2-to-the-2nd power (2x2=4), meaning that 4 shades of color are available for each of the three primary colors (red, blue, and green). 4-bit color (2x2x2x2=16) means that each of the primaries has 16 shades; the greater the bit depth, the more shades for each color. See the chart below for a comparison of bit depth and color resolution. —Ed.] 256-Color Mode: uses only 8 bits (2 bits for blue, 3 for green, 3 for red). Choosing between only 4 or 8 different values for each color would result in poor blocky color, so a different approach is taken instead: the use of a palette. A palette is
created containing 256 different colors. Each one is defined using the standard 3byte color definition that is used in true color: 256 possible intensities for each of red, blue, and green. Each pixel is allowed to choose one of the 256 colors in the palette, which can be considered a "color number" of sorts. So the full range of color can be used in each image, but each image can only use 256 of the available 16 million different colors. When each pixel is displayed, the video card looks up the real RGB values in the palette based on the "color number" the pixel is assigned. The palette approach is an excellent compromise: it allows only 8 bits to be used to specify each color in an image, but allows the creator of the image to decide what the 256 colors in the image should be. Since virtually no images contain an even distribution of colors, this allows for more precision in an image by using more colors than would be possible by assigning each pixel a 2-bit value for blue and 3-bit values each for green and red. For example, an image of the sky with clouds would have many different shades of blue, white, and gray, and virtually no reds, greens, or yellows. 256-color is the standard for much of computing, mainly because the higherprecision color modes require more resources (especially video memory) and aren't supported by many PC's. Despite the ability to "hand pick" the 256 colors, this mode produces noticeably worse image quality than high color, and most people can tell the difference between high color and 256-color mode. High color: 16-bit color—uses two bytes of information to store the intensity values for the three colors. This is done by breaking the 16 bits into 5 bits for blue, 5 bits for red, and 6 bits for green, giving 32 different intensities for blue, 32 for red, and 64 for green. This reduced color precision results in a slight loss of visible image quality, but it is actually very slight—most people cannot see the differences between true color and high color images unless they are looking for them. For this reason high color is often used instead of true color—it requires 33% (or 50% in some cases) less video memory, and it is also faster for the same reason. True color: 24-bit color—three bytes of information are used, one for each of the red, blue, and green signals that make up each pixel. Since a byte has 256 different values, each color can have 256 different intensities, using over 16 million different color possibilities, and allowing for a very realistic representation of the color of images, with no compromises necessary and no restrictions on the number of colors an image can contain. In fact, 16 million colors is more than the human eye can discern, though true color is necessary for doing high-quality photo editing, graphic design, etc. [Some video cards have to use 32 bits of memory for each pixel when operating in true color, due to how they use the video memory.] [TheScreamOnline is best viewed with 24-bit color, or millions of colors, though thousands of colors will suffice. On a Mac, go to Control Panels > Monitors (see
graphic above under Adjusting Resolution) and set the color depth to thousands or millions of colors if your video card supports it. Lowering the resolution of your screen display may allow you to achieve a greater color depth. On a Windows computer, go to Start Menu > Settings > Control Panels > Display > Settings. —Ed.] BIT DEPTH
COLOR RESOLUTION
CALCULATION
1-bit
2 colors
2 (2)
2-bit
4 colors
2 (2x2)
3-bit
8 colors
2 (2x2x2)
4-bit
16 colors
2 (2x2x2x2)
5-bit
32 colors
2 (2x2x2x2x2)
6-bit
64 colors
2 (2x2x2x2x2x2)
7-bit
128 colors
2 (2x2x2x2x2x2x2)
8-bit
256 colors
2 (2x2x2x2x2x2x2x2)
16-bit
65,536 colors
2
24-bit
16,777,215 colors
2
Monitors vs. Browsers Four variables tend to make the life of a web designer a living hell. Macintosh monitors display text at 72 dpi (dots-per-inch) and PC's take 96 pixels to show that same text. Translation: a PC monitor enlarges the type—sort of like reading a large-print novel. Differences in the two major browsers (Netscape and Internet Explorer) also add to the problem. Netscape is close to WYSIWYG (What You See Is What You Get)—it doesn't significantly change how a webpage is meant to appear. Internet Explorer (or IE), on the other hand, enlarges text one-to-two point sizes. So, a page of text can appear four different ways, depending on the combination: Netscape on a Mac, IE on a Mac, Netscape on a PC, and IE on a PC. The difference between viewing a page on a Mac using the Netscape browser and that same page on a PC with IE is enormous. A lot of seemingly unnecessary time is spent by web designers trying to "dumbdown" a site so that it looks acceptable in all formats. Many designers, however, say "To hell with those with cheap equipment," and create a site for users with high-end gear. If only the two platforms and browsers could conform to a standard, then most of these woes wouldn't exist and not only could designers focus more on the quality of the design itself, the product would be better and the end-user (you!) would consistently see websites as they were meant to be viewed.
Caveat Emptor Many of the low-price "deals" that come with PC packages can include—in addition to the requisite monitor, CPU, and keyboard—a modem, scanner, Zip drive, printer, and CD-rom drive. Be careful—you get what you pay for. Much of the time you will end up with a very inexpensive 8-bit 640 x 480 monitor that cannot be adjusted. While a good monitor (large size with a high resolution/bandwidth/refresh rate and small dot pitch) will hold its value for some time, CPU's will be worth only a fraction of their original cost after about a year. If you just use a computer for basic word-processing and email communications, then the cheap route is probably adequate. Beyond that, you will quickly realize the limitations of your purchase. If you are serious about creating, or at least viewing, high-quality images, in addition to viewing websites as they are meant to be seen, then it would be wise to invest in the appropriate equipment.
Interface Monitor Overview
The Interface Monitor Plugin gives you a detail and synthetic view of a network interface status. The use of the MIB II standard allows you to get this information of almost all system and network devices. The % of the current load is diplayed in a line graph and tells you in a blink of one eye if your interface is overloaded. You can specify a pourcentage of load (threshold) that will generate an alarm if this one is reached.
Installation The installation of the Interface Monitor Plugin is performed in the directory workspace. Select one host in your directory and then from the contextual Menu select Insert Task and Plugin.
You should see the following result in your workspace.
By a double click on the hammer icon you should start the Plugin Dialog Window and could configure it.
Configuration The configuration of the Interface Monitor is performed directly in the Plugin main window. Few parameter have to be set. You should first select an interface frome the list.
You should set a polling interval. If the polling interval is high the line graph x scale will be bigger and thus you will have a view on a longer time period.
If you want to be warn when a load threshold is reached you have to set up the three fields.
"If usage >" parameter specifies the load threshold in % above which you want to be warn. "Send Event" parameter should contain the event number displayed in the event manager (value should be unique within your set of events and higher than 10000). The "At level" value (between 0 and 10) specifies the gravity of the alarm and the color of the event. The screen below shows you example of alarm for each severity level.
Supervision The information provided by the various indicators present in the screen are all very instructive and give rich information on the interface traffics and errors. Here is the list of these indicators. Graph : Incoming/Outgoing for interface index ... Graph : Interface load in % Graph : Packets in Error Graph : Packets Discarded Information ifAdminStatus (Interface Administrative Status) ifinUnknowProtos (Interface Inbound unknow Protocol) ifinUcastPkts (Interface Inbound Unicast Packets) ifinNUcastPkts (Interface Inbound Non-Unicast packets) ifOperStatus (Interface Operational Status) ifOutQlen (Interface Output Queue lenght) ifOutUcastPkts (Interface Out Unicast packets) ifOutNUcastPkts (Interface Out Non-unicast Packets) Broadcast and Multicast Rx discard Pkts/s (Received Packets discarded) Tx discard Pkts/s Rx error Pkts/s Tx error Pkts/s Rx broad Pkts/s Tx broad Pkts/s
Graph : Incoming/Outgoing for interface index ... This graph displays the number of octets sent and received by the interface. The in (yellow) line display the incoming octet value, the out (purple) line displays the ougoing octet value. Both value comes from the ifOutOctets OID (The total number of octets transmitted out of the interface, including framing characters) and ifInOctects OID (The total number of octets received on the interface, including framing characters.
The y-axis displays octet values, the x-axis is the time scale. The value displayed on the y-axis is the number of inbound or ounbond Octets counted during the polling interval. The octet value depends from the polling interval selection. if you want to know the octet/second values you should do the following conversion. y-axis value / Polling interval = Octets per second (average) If you want to have a speed value in bits per second the formula is : (y-axis value / Polling interval) * 8 = Bits per second (average) With this formula, remenber that more the polling interval is high more the value is averaged. In other words, if your traffic contains surges you could miss them. The following table gives you examples of values for various interface types, various polling intervals and various loads.
Number of octets per polling interval Interface type Load
Interface Speed Mbps
1 seconds 5 secondes 8 seconds
10 seconds
30 seconds
60 seconds
5 mn
4 000 octets/s 50 % load on LL 64 Kbps
64 000
4 000
20 000
32 000
40 000
120 000
240 000
1 200 000
8 000 octets/s 100 % load 64 000 on LL 64 Kpbs
8 000
40 000
64 000
80 000
240 000
480 000
2 400 000
125 000 octets/s 50 % load on E1 line
125 000
625 000
1 000 000
1 250 000
3 750 000
7 500 000
37 500 000
2 000 000
250 000 octets/s 2 000 000 100 % load on E1 line
250 000
1 250 000
2 000 000
2 500 000
7 500 000
15 000 000
75 000 000
625 000 octets/s = 50% load 10 000 000 625 000 on Ethernet 100 Mbps
3 125 000
5 000 000
6 250 000
18 750 000
37 500 000
187 500 000
1 250 000 octets/s = 100% load on Ethernet 100 Mbps
1 250 000
6 250 000
10 000 000
12 500 000
37 500 000
75 000 000
375 000 000
6 250 000 octets/s 100 000 = 50% load 000 on Ethernet 100 Mbps
6 250 000
31 250 000
50 000 000
62 500 000
187 500 000
375 000 000
1 875 000 000
12 500 000 octets/s = 100% 100 000 load on 000 Ethernet 100 Mbps
12 500 000
62 500 000
100 000 000
125 000 000
375 000 000
750 000 000
3 750 000 000
10 000 000
Graph : Interface load in %
This graph displays the percentage of load for the interface. Two lines, one for the incoming traffic, one for the outgoing traffic are represented.
The -
reading
%
the
of interface
load speed
is value
in
calculated Bits/s
by (ifSpeed
: OID)
- reading the current throughput in - and by applying the following formula :
Octets/s
(ifIinOctets
and
ifOutOctets
OIDs)
(Octets per second / Polling interval) / ((Speed of interface in Bits per second) / 8 / 100 ) The maximum reached by one of both indicator is displayed as a white line and its value is indicated on the right side (82.10 % for the Inbound load in our example).
Graph : Packets in Error Error packet are malformed packet at the link control layer, Ethernet for example, that could not be used by upper applications. The maximum reached by one of both indicators is displayed as a white line and its value is indicated on the right side.
The value displayed on the y-axis is the number of inbound or outbound packets counted during the polling interval. This table gives you the value in Pkts/s and their corresponding values for various polling interval .
Number of packets per polling interval 1 seconds 5 secondes 8 seconds 10 seconds 30 seconds 60 seconds 5 mn 10 Pkts/s
10
50
80
100
300
600
3000
100 Pkts/
100
500
800
1 000
3 000
6 000
30 000
1 000 Pkts/s
1 000
5 000
8 000
10 000
30 000
60 000
300 000
10 000 Pkts/s
10 000
50 000
80 000
100 000
300 000
600 000
3 000 000
In our screen shot the maximum value recorded is 5817 packets. It gives us an average of 1164 Packet per second.
Graph : Packets Discarded The graph displays the number of inbound and outbound packets which were chosen to be discarded even though no errors had been detected to prevent their being deliverable to a higher-layer protocol. One possible reason for discarding such a packet could be to free up buffer space. The maximum reached by one of both indicator is displayed as a white line and its value is indicated on the right side.
The value displayed on the y-axis is the number of inbound or outbound packets counted during the polling interval.
Information This
field
displays
information
about
the
Network
interface.
Description. The name given to the interface for better identification Type. The type of interface, distinguished according to the physical/link protocol(s) immediately below the network layer in the protocol stack. MTU (maximum Transmit Unit). The size of the largest datagram which can be sent/received on the interface, specified in octets. For interfaces that are used for transmitting network datagrams, this is the size of the largest network datagram that can be sent on the interface. Speed. An estimate of the interface's current bandwidth in bits per second. For interfaces which do not vary in bandwidth or for those where no accurate estimation can be made, this object should contain the nominal bandwidth. Physical address. The interface's address at the protocol layer immediately `below' the network layer in the protocol stack. For interfaces which do not have such an address (e.g., a serial line), this object should contain an octet string of zero length.
ifAdminStatus - Interface Administrative Status
The desired state of the interface. The states could be :
• • •
up(1) ready to send or receive packets down(2) unable to send or receive packets testing(3) in some test mode
The testing(3) state indicates that no operational packets can be passed.
ifinUnknowProtos - Interface Inbound Unknown Protocols The number of packets received via the interface which were discarded because of an unknown or unsupported protocol. Accepted protocols should be supported by the type of interface. ifinUcastPakts - Interface Inbound Unicast Packets The
number
of
subnetwork-unicast
packets
delivered
to
a
higher-layer
protocol.
ifinNUcastPkts - Interface Inbound Non-Unicast Packets (Broadcast and Multicast) The number of non-unicast (i.e., subnetwork- broadcast or subnetwork-multicast) packets delivered to a higher-layer protocol. ifOperStatus - Interface Operational Status The current operational state of the interface.
• • • The packets
up(1) ready to send or receive packets down(2) unable to send or receive packets testing(3) in some test mode
testing(3)
state can
indicates
that be
no
operational passed.
ifOutQlen - Interface Output Queue Lenght The
length
of
the
output
packet
queue
(in
packets)
ifOutUcastPkts - Interface Outbound Unicast Packets The total number of packets that higher-level protocols requested be transmitted to a subnetwork-unicast address, including those that were discarded or not sent. ifOutNUcastPkts - Interface Outbound Non-Unicast Packets The total number of packets that higher-level protocols requested be transmitted to a nonunicast (i.e., a subnetwork-broadcast or subnetwork-multicast) address, including those that were discarded or not sent.
Rx discard Pkts/s
The average value of received packets discarded per second during the polling interval Tx discard Pkts/s The average value of transmitted packets in error per second during the polling interval Rx error Pkts/s The average value of received packets in error per second during the polling interval Tx error Pkts/s The average value of transmitted packets in error per second during the polling interval Rx broad Pkts/s The average value of broadcast packet received per second during the polling interval Tx broad Pkts/s The average value of broadacst packet transmitted per second during the polling interval
