Right, I believe any router running code written within the last 5 years supports it today. It is very mature at this point.
Leah From: Kenny Sallee [mailto:[email protected]] Sent: Saturday, April 10, 2010 10:05 PM To: Leah Lynch (Contractor) Cc: Dan Goldberg; [email protected] Subject: Re: [c-nsp] BGP as-path access list question on 1841 routers That depends on if both BGP neighbors support route refresh capability I think. Looks like it's negotiated upon BGP neighbor establishment: 001052: *Apr 10 18:32:18.372 PDT: BGP: <ip> OPEN has ROUTE-REFRESH capability(old) for all address-families 001053: *Apr 10 18:32:18.372 PDT: BGP: <ip> rcvd OPEN w/ optional parameter type 2 (Capability) len 2 001054: *Apr 10 18:32:18.372 PDT: BGP: <ip> OPEN has CAPABILITY code: 2, length 0 001055: *Apr 10 18:32:18.372 PDT: BGP: <ip> OPEN has ROUTE-REFRESH capability(new) for all address-families 001056: *Apr 10 18:32:18.372 PDT: BGP: <ip> rcvd OPEN w/ optional parameter type 2 (Capability) len 3 Kenny On Thu, Apr 1, 2010 at 12:11 PM, Leah Lynch (Contractor) <[email protected]> wrote: Avoid the soft-reconfiguration statement altogether, it is a legacy command that stores an extra copy of the table. Just use clear ip bgp in, that will use the route refresh capability without any extra configuration or memory use. Leah -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Kenny Sallee Sent: Thursday, April 01, 2010 12:03 PM To: Dan Goldberg Cc: [email protected] Subject: Re: [c-nsp] BGP as-path access list question on 1841 routers You don't need to specify the 'soft-reconfiguration' under the bgp neighbor but I believe you still should do a clear ip bgp nei <ip> soft in|out or clear ip bgp nei <ASN> soft in|out Kenny On Thu, Apr 1, 2010 at 11:45 AM, Dan Goldberg <[email protected]> wrote: > > I left out a detail that may be important: > This is on an MPLS WAN where I control all the CEs. The PEs are all > provider controlled. > The "hubs" I mentioned are just larger CEs with a broader BGP policy > permitting all my AS numbers. So each routers neighbor is not under my > control. > > Thanks again. > Dan > > -----Original Message----- > From: [email protected] [mailto: > [email protected]] On Behalf Of Dan Goldberg > Sent: Thursday, April 01, 2010 1:10 PM > To: [email protected] > Subject: [c-nsp] BGP as-path access list question on 1841 routers > > Hi there, > I have what is probably a very simple BGP question which I wanted to ask. > The short version is how to refresh/reread an existing BGP as-path > access-list (with new permits added) without rebooting the router? > > The long version: > I run primarily IOS Version 12.4(15)T9 on 1841s with EBGP configured > largely as follows. I have roughly 100 sites like this. For the most part > all sites have connectivity to 2 "hubs", a NOC and an alternative (BCP) NOC. > Tail sites are not supposed to be able to reach each other or even know > about each other (through BGP) in most cases. That is what the as-path > access list provides. > > There are some cases where there are groups of ASes that I want to allow > BGP to learn about each other. These relationships are built sometimes > arbitrarily. > > <all numbers are faked> > router bgp 65534 > network blah mask 255.255.255.255 > neighbor www.xxx.yyy.zzz remote-as 65533 > neighbor www.xxx.yyy.zzz filter-list 1 in > ! > ip as-path access-list 1 permit 64542 > ip as-path access-list 1 permit 64543 > > I have found that if I start with the above as-path filter and then add a > new permit to the filter as below: > ip as-path access-list 1 permit 64551 > > #sho ip bgp neighbors shows: > Neighbor capabilities: > Route refresh: advertised and received(old & new) > > The question (finally): > Can I use a soft restart to re-read the as-path access-list? > Do I need to add a "neighbor soft-reconfiguration" statement to BGP first? > Is there another method to force a reread of the filter-list without losing > connectivity to the router? > > Thanks I appreciate your feedback. > > -- > Dan Goldberg > <title removed due to other thread> > Video Gaming Technologies, Inc. > 434-992-5450 > > > _______________________________________________ > cisco-nsp mailing list [email protected] > https://puck.nether.net/mailman/listinfo/cisco-nsp > archive at http://puck.nether.net/pipermail/cisco-nsp/ > > _______________________________________________ > cisco-nsp mailing list [email protected] > https://puck.nether.net/mailman/listinfo/cisco-nsp > archive at http://puck.nether.net/pipermail/cisco-nsp/ > _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/ This email may contain confidential and privileged material for the sole use of the intended recipient. 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