RE: Default Weight in BGP [7:38191]
Actually the value is from 0 to 65535, but this does bring up a questionIf weight is used internally on a router to prefer one egress path over another, and the attribute is never advertised to it's peers, then why would Cisco say the following about the Weight attribute: The administrative weight is local to the router. A weight can be a number from 0 to 65535. Any path that a Cisco router originates will have a default weight of 32768; other paths have weight 0 I guess I'm confused about this statement. If it's an internal-only value, then how would a Cisco router ever use a value of 0? Are they giving us information about other vendors products here, since as I understand it, weight is a Cisco proprietary attribute? Confused, Kelly Cobean, CCNP,CCSA, ACSA, MCSE, MCP+I -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] Sent: Thursday, March 14, 2002 12:24 AM To: [EMAIL PROTECTED] Subject: Re: Default Weight in BGP [7:38191] Just out of intrest, what does that have to do with BGP weights? BGP weights are used to define the exit point from a router when you want to perfer one path over another, cisco's default is 32768 but I think the weight can be anything up to 4million... Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=38218t=38191 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: Default Weight in BGP [7:38191]
Weight, like all BGP attributes, is present for EVERY route in the BGP table. So, if the route is sourced from another router, it will need to be assigned a weight. The assigned weight will be 0. (Weight has local-significance only, and is not transited) So, routes sourced locally will have a local weight of 32k. Routes sourced remotely will have a weight of 0. Using route-maps, you can adjust these weights if needed. As to why it's 32k, I assume it has something to do with the fact that the BGP table is de-coupled from the routing table, and ensuring that routers advertize themselves as the best-path as oposed to chosing another BGP route as best. However, this is off the top of my head, I'm sure Halabi or Doyle would have more on this in their books. --Wes Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=38274t=38191 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: Default Weight in BGP [7:38191]
sorry about the non sequiter. one of those nights... Chuck wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... interesting way to put the question. but.. 172.16.0.0/12 and 192.168.0.0/16 are CIDR notation. any subnets within those ranges would default to the classfull values based upon the first couple of bits. remembering that 0 in the first position is class A, 10 in the first two positions indicate class B, and 110 in the first three positions indicate class C. RIP and IGRP are classful, and would note the classful values. Cebuano wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... Another simple question for all BGP gurus. What's the point of a Cisco router assigning a default weight of 32768 for paths it originates? Thanks. Elmer Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=38196t=38191 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: Default Weight in BGP [7:38191]
interesting way to put the question. but.. 172.16.0.0/12 and 192.168.0.0/16 are CIDR notation. any subnets within those ranges would default to the classfull values based upon the first couple of bits. remembering that 0 in the first position is class A, 10 in the first two positions indicate class B, and 110 in the first three positions indicate class C. RIP and IGRP are classful, and would note the classful values. Cebuano wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... Another simple question for all BGP gurus. What's the point of a Cisco router assigning a default weight of 32768 for paths it originates? Thanks. Elmer Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=38194t=38191 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: Default Weight in BGP [7:38191]
Just out of intrest, what does that have to do with BGP weights? BGP weights are used to define the exit point from a router when you want to perfer one path over another, cisco's default is 32768 but I think the weight can be anything up to 4million... Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=38200t=38191 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
