09-21-2007 10:22 AM - edited 03-03-2019 06:52 PM
when I do a sh ip bgp community ? I get the following on two routers.
route-views.oregon-ix.net>sh ip bgp community ?
aa:nn community number
local-AS Do not send outside local AS (well-known community)
no-advertise Do not advertise to any peer (well-known community)
no-export Do not export to next AS (well-known community)
| Output modifiers
<cr>
jo100-r5>sh ip bgp comm
jo100-r5>sh ip bgp community ?
<1-4294967295> community number
local-AS Do not send outside local AS (well-known community)
no-advertise Do not advertise to any peer (well-known community)
no-export Do not export to next AS (well-known community)
| Output modifiers
<cr>
one router has a community number <1-4294967295> and the other one has aa:nn
what is the difference? Is it IOS feature?
Solved! Go to Solution.
09-21-2007 10:36 AM
Chandra
Yes it is an IOS feature. You can use the command ip bgp-community new-format to have the router format the community with the AS:value format.
HTH
Rick
09-21-2007 10:39 AM
Yes, this is an IOS feature. The first router has what is called a "new format" of BGP community. They are both 32 bit numbers, but in "new format" the community is specified in "aa:nn" where "aa" is your AS number and "nn" is an arbitrary number. It was created for practival purposes, because 65000:1 was easier to write and manage than for example 3128683542.
To turn on or off the new format feature use "ip bgp-community new-format" global configuration command.
Hope this helps.
Please rate all helpful posts.
09-21-2007 10:36 AM
Chandra
Yes it is an IOS feature. You can use the command ip bgp-community new-format to have the router format the community with the AS:value format.
HTH
Rick
09-21-2007 10:39 AM
Thanks, for the help
09-21-2007 10:39 AM
Yes, this is an IOS feature. The first router has what is called a "new format" of BGP community. They are both 32 bit numbers, but in "new format" the community is specified in "aa:nn" where "aa" is your AS number and "nn" is an arbitrary number. It was created for practival purposes, because 65000:1 was easier to write and manage than for example 3128683542.
To turn on or off the new format feature use "ip bgp-community new-format" global configuration command.
Hope this helps.
Please rate all helpful posts.
09-21-2007 10:39 AM
Chandrathilaka,
The following command is configured on the first but not on the second router:
R1(config)#ip bgp ?
new-format select aa:nn format for BGP community
Regards,
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