On Wed, Jul 28, 2010 at 8:28 PM, Miya Kohno <mko...@juniper.net> wrote: > 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.
not arguing that, though for the purposes of the router's view these 2 addresses are in fact adjacent on the same link. dthayler's issue is purely (I think) semantic with respect to the ipv6 rfc portions of the discussion... 'if you say slash-27, you must deal with all this other baggage. if you say off-link addresses which may happen to be adjacent, you do not.' is it 'ok' to define this term differently in each document/context? -chris > Miya > -----Original Message----- > From: Christopher Morrow [mailto:christopher.mor...@gmail.com] > Sent: Thursday, July 29, 2010 7:53 AM > To: Miya Kohno > Cc: Hemant Singh (shemant); dtha...@wollive.windowsmedia.com.akadns.net; > ipv6@ietf.org > Subject: Re: 6man discussion on /127 document @ IETF78 > > On Wed, Jul 28, 2010 at 11:58 AM, Miya Kohno <mko...@juniper.net> 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 >> ipv6@ietf.org >> Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 >> -------------------------------------------------------------------- >> > -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
