Naletel sem na težave na enem od naših IPv6 peeringov, kjer na oni strani uporabljajo Quagga BGP routing daemon. Njihov router nam je v BGP annoucement-ih vztrajno pošiljal prefikse z next-hop ::, naš router pa jih ni sprejel s pojasnilom:

May 25 12:42:52.357 CET: BGP: X unspecified nexthop :: (::)
May 25 12:42:52.361 CET: BGP(1): X rcv UPDATE w/ attr: nexthop ::, origin i, metric 0, originator 0.0.0.0, path 65500, community , extended community , SSA attribute
May 25 12:42:52.361 CET: BGPSSA ssacount is 0
May 25 12:42:52.361 CET: BGP(1): X rcv UPDATE about Y -- DENIED due to: martian MP_REACH NEXTHOP;

Zadevo sem preizkusil v testnem okolju z naslednjo konfiguracijo Quagge (verzija 0.98.6):

router bgp 65500
bgp router-id 10.10.10.10
no bgp default ipv4-unicast
neighbor 2001:1470:3004:1fff:0:268:0:ffff remote-as 2107
!
address-family ipv6
network 2001:1470:8000:c0b::/64
neighbor 2001:1470:3004:1fff:0:268:0:ffff activate

Quagga res oglašuje prefiks(e) z next-hop-om ::. To tudi “brez sramu prizna”:

master# show bgp ipv6 neighbors 2001:1470:3004:1FFF:0:268:0:ffff advertised-routes
BGP table version is 0, local router ID is 10.10.10.10
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal
Origin codes: i - IGP, e - EGP, ? - incomplete

Network Next Hop Metric LocPrf Weight Path
*> 2001:1470:8000:c0b::/64
:: 0 32768 i

Total number of prefixes 1

Z naslednjim “hack-om”:

route-map NextHop6 permit 1
set ipv6 next-hop global 2001:1470:3004:1FFF:0:268:0:1
!
router bgp 65500
address-family ipv6
neighbor 2001:1470:3004:1fff:0:268:0:ffff route-map NextHop6 out

…sem nastavil pravilen “next-hop”, vendar mi ta rešitev nikakor ni všeč. Na podoben pojav na opremi, s katero imam več izkušenj (Cisco, Juniper), še nisem naletel. Ima kdo (poleg Jana, seveda) kaj več izkušenj s tem? Kako Quaggo “nahecati”, da uporabi pravi next-hop v BGP announcement-ih?

V naprej hvala za feedback!

Matjaž6

Vaš IP naslov (ali ste na IPv6 ?):
3.14.132.178

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