Re: bandwidth in serial interface [7:48481]
On Wed, 10 Jul 2002, Deepak Achar wrote: i have this doubt.What is the significance of Bandwidth command in the serial interface.coz' whatever the bandwidth configured on the serial interface will not be the actual bandwidth which the serial interface is carrying. pls can any one clarify my doubt? Its used by various routing protocols to calculate metrics (I'm sure there's more than just EIGRP, but thats the only one I can think of off the top of my head... gurrr, after work vagueness). Its also used to calculate the load counter in a 'show interface' command. This interface is a 1.2Mbit serial circut. With the cisco default of 1.544Mbit, load is as follows... MTU 1500 bytes, BW 1544 Kbit, DLY 2 usec, reliability 255/255, txload 37/255, rxload 82/255 But by adding 'bandwidth 1200' command to the interface, the loads look more correct (with the same amount of traffic on the circut). MTU 1500 bytes, BW 1200 Kbit, DLY 2 usec, reliability 255/255, txload 49/255, rxload 106/255 Rgds, - I. -- Ian Henderson CCNA, CCNP Senior Network Engineer, Chime Communications Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=48483t=48481 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: bandwidth in serial interface [7:48481]
Deepak, The bandwidth statement only serves to inform the routing protocol (depending on the protocol of course!) as to the real bandwidth of the interface - ie - what is the clock-rate - how many bits per second can the interface shift! This way the routing protocol knows which is the better link If the bandwidth command is omitted and you have 2 links which are actually 128k and 64k in reality , ospf would see these links as equal! HTH Richard Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=48484t=48481 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: bandwidth in serial interface [7:48481]
The bandwidth command is for proper function of routing protocols. The routing protocol will take the value of the bandwidth statement and use it in its metric. Tim CCIE 9015 -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] Sent: Wednesday, July 10, 2002 5:11 AM To: [EMAIL PROTECTED] Subject: bandwidth in serial interface [7:48481] hi i have this doubt.What is the significance of Bandwidth command in the serial interface.coz' whatever the bandwidth configured on the serial interface will not be the actual bandwidth which the serial interface is carrying. pls can any one clarify my doubt? regards deepak Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=48485t=48481 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: bandwidth in serial interface [7:48481]
It's there as a metric for routing calculations, not as a real measure of link load or capability. At 09:11 AM 7/10/2002 +, you wrote: hi i have this doubt.What is the significance of Bandwidth command in the serial interface.coz' whatever the bandwidth configured on the serial interface will not be the actual bandwidth which the serial interface is carrying. pls can any one clarify my doubt? regards deepak Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=48486t=48481 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: bandwidth in serial interface [7:48481]
Bandwidth is just a nominal value that has nothing to do with the actual bandwidth which the serial interface is carrying. You would need to modify the default bandwidth value to a different one in the following cases: 1- To have meaningful readings out of the txload, rxload. For example The default bandwidth would be a T1 while your circuit is 128K. You will run into cases where you are fully utilizing the 128K and still txload,rxload doesn't show 255/255 to indicate link is full. What you will get in such a case 21/255 because it is referring to the default bandwidth of the interface not the actual speed. 2- In situations when you want more control over load-balancing between the interfaces. For example if you are running a dynamic routing protocol it would use such nominal value in its calculations for load-balancing the traffic over the interfaces. You will end in situations where you have to modify the default bandwidth to acheive your target in load-balancing. Yasser hi i have this doubt.What is the significance of Bandwidth command in the serial interface.coz' whatever the bandwidth configured on the serial interface will not be the actual bandwidth which the serial interface is carrying. pls can any one clarify my doubt? regards misconduct and Nondisclosure violations to [EMAIL PROTECTED] Chat with friends online, try MSN Messenger: Click Here Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=48487t=48481 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: bandwidth in serial interface [7:48481]
No, actually it's not a real measure of link load or capability. The link load parameter is a function of the bandwidth parameter, but it's not at all related to the actual bandwidth, or load, of the link. For example, I can take a 64Kbit link (actual bandwidth) and assign a bandwidth parameter of 1.544Mbits. The router won't care and will use 1.544Mbits as the bandwidth metric used to calculate routes (and reported load). So, the actual load on the link may be 100%, but the load ratio may only show 10/255. At 01:43 PM 7/10/2002 +0300, you wrote: It is as a real measure of link load too. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Craig Columbus Sent: Wednesday, July 10, 2002 1:30 PM To: [EMAIL PROTECTED] Subject: Re: bandwidth in serial interface [7:48481] It's there as a metric for routing calculations, not as a real measure of link load or capability. At 09:11 AM 7/10/2002 +, you wrote: hi i have this doubt.What is the significance of Bandwidth command in the serial interface.coz' whatever the bandwidth configured on the serial interface will not be the actual bandwidth which the serial interface is carrying. pls can any one clarify my doubt? regards deepak Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=48488t=48481 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: bandwidth in serial interface [7:48481]
hi all Thanks a lot for ur inputs.it cleared my doubt on the topic. regards deepak Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=48573t=48481 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
