Hi Chris, According to the rfc4861, "off-link" is defined as follows: "the opposite of "on-link"; an address that is not assigned to any interfaces on the specified link."
BGP checks if an eBGP peer is directly connected by comparing the peer address against directly connected interface addresses. So I was afraid it could be incompatible. Miya -----Original Message----- From: Christopher Morrow [mailto:[email protected]] Sent: Thursday, July 29, 2010 7:53 AM To: Miya Kohno Cc: Hemant Singh (shemant); [email protected]; [email protected] Subject: Re: 6man discussion on /127 document @ IETF78 On Wed, Jul 28, 2010 at 11:58 AM, Miya Kohno <[email protected]> wrote: > Hi, > >>> The draft is discussing about inter-router backbone link, where >>> "directly-connected neighbor" has a significant meaning from >>> routing protocol point of view. So it needs to be assumed "on-link". > >> Even if the two routers are in the off-link model for the IPv6 address 'off link' does not (for the case of this discussion) mean 'off the ethernet wire', it's a semantic distinction that thayler and shermant are attempting to make in order to keep the authors from having to go off and muck with a bunch of other already finalized documents. So... in short 'off link' just means 'dont call this a /127, call this two ips that happen to live together on the same piece of ethernet/sonet/frame/wifi' -chris >> and RA configuration, the network between the two routers is still a >> directly connected network. One router sends his packet to the other >> without going thru any routed hop. So what specifically fails for BGP >> with an off-link addressing and RA configuration? > > A quote from IOS manual: > > ------------------ > A BGP routing process will verify the connection of single-hop eBGP > peering session (TTL=254) to determine if the eBGP peer is directly > connected to the same network segment by default. If the peer is not > directly connected to same network segment, connection verification will > prevent the peering session from being established. > ------------------ > http://cisco.biz/en/US/docs/ios/12_3t/ip_route/command/reference/ip2_n1g > t.html#wp1109875 > > Miya > -------------------------------------------------------------------- > IETF IPv6 working group mailing list > [email protected] > Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 > -------------------------------------------------------------------- > -------------------------------------------------------------------- IETF IPv6 working group mailing list [email protected] Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
