On Tue, 30 Oct 2001, Scott Whyte wrote:
>
> This might be CSCdu10278. What IOS are you running?
Whups missed the show ver. This looks pretty likely.
-Scott
> On Mon, 29 Oct 2001, Sergey V. Artjushkin wrote:
>
> > Hello Colleagues.
> >
> > My name is Sergey Artjushkin. I'm network engineer of
> > ISP "Caravan" (Moscow).
> >
> > I have tow bgp peering with ISP1 and ISP2, for example.
> > ISP1 advertise to me full bgp table and default route, ISP2 advertise
> > only default route. ISP2 is a backup link for my network. Despite the
> > fact, that to ISP2 I advertise my network with 7 prepend (!) I have
> > inbound traffic on this link. To solve this problem I have decided to
> > use bgp conditional advertising. If bgp link to ISP1 is up, I advertise
> > to ISP1 my networks, and nothing advertise to ISP2. If ISP1 is down,
> > I have to advertise to ISP2 my networks.
> > For writing non-exist-map I decided to use prefix 1.0.0.0/8 (this prefix
> > is not real) that I receive from ISP2. SO I writed the following
> > configuration:
> >
> > -----------------------------------------------------------
> > neighbor 1.1.1.1 remote-as 1111
> > neighbor 1.1.1.1 next-hop-self
> > neighbor 1.1.1.1 prefix-list ZAPAD-OUT out
> > neighbor 1.1.1.1 route-map SET-ZAPAD-COMM in
> > neighbor 2.2.2.2 remote-as 2222
> > neighbor 2.2.2.2 ebgp-multihop 255
> > neighbor 2.2.2.2 next-hop-self
> > neighbor 2.2.2.2 prefix-list ZAPAD-OUT out
> > neighbor 2.2.2.2 route-map SET-ZAPAD-COMM in
> > neighbor 2.2.2.2 advertise-map ZAPAD-OUT non-exist-map TTT
> > !
> > access-list 6 permit 1.0.0.0 0.255.255.255
> > !
> > route-map ZAPAD-OUT permit 5
> > match ip address prefix-list CARAVAN
> > set as-path prepend 15756 15756 15756 15756 15756
> > !
> > ip prefix-list CARAVAN seq 5 permit 217.23.128.0/19
> > ip prefix-list ZAPAD-OUT seq 5 permit 217.23.128.0/19
> > !
> > route-map TTT permit 5
> > match ip address 6
> > ---------------------------------------------------------
> >
> > So, If prefix 1.0.0.0/8 is received from ISP1, to ISP2 nothing should
> > be advertised. Am I right? I think, I'm right. But this configuration
> > is NOT WORKING. Undepending of existence 1.0.0.0/8 to IPS2 nothing is
> > advertised. Diagnostic is following:
> >
> > ----------------------------------------------------------
> > c7200.caravan.ru#sh ip bgp sum | in 2222
> > 2.2.2.2 4 2222 1119 1130 10148290 0 0 00:16:27 1
> >
> > c7200.caravan.ru#sh ip bgp 1.0.0.0/8
> > % Network not in table
> >
> > c7200.caravan.ru#sh ip bgp nei 2.2.2.2 ad
> >
> > c7200.caravan.ru#
> >
> > c7200.caravan.ru#sh ip bgp neighbors 2.2.2.2
> > BGP neighbor is 2.2.2.2, remote AS 2222, external link
> > BGP version 4, remote router ID 2.2.2.2
> > BGP state = Established, up for 00:00:52
> > Last read 00:00:50, hold time is 180, keepalive interval is 60 seconds
> > Neighbor capabilities:
> > Route refresh: advertised and received(new)
> > Address family IPv4 Unicast: advertised and received
> > Received 1124 messages, 0 notifications, 0 in queue
> > Sent 1134 messages, 0 notifications, 0 in queue
> > Route refresh request: received 1, sent 0
> > Default minimum time between advertisement runs is 30 seconds
> >
> > For address family: IPv4 Unicast
> > BGP table version 10148498, neighbor version 10148498
> > Index 6, Offset 0, Mask 0x40
> > NEXT_HOP is always this router
> > Inbound path policy configured
> > Outgoing update prefix filter list is ZAPAD-OUT
> > Route map for incoming advertisements is SET-ZAPAD-COMM
> > Condition-map TTT, Advertise-map ZAPAD-OUT, status: Uninitialized
> > 1 accepted prefixes consume 36 bytes
> > Prefix advertised 10, suppressed 0, withdrawn 4
> > Number of NLRIs in the update sent: max 1, min 0
> >
> > Connections established 3; dropped 2
> > Last reset 00:01:14, due to User reset
> > External BGP neighbor may be up to 255 hops away.
> > Connection state is ESTAB, I/O status: 1, unread input bytes: 0
> > Local host: 2.2.2.2.1, Local port: 49646
> > Foreign host: 2.2.2.2, Foreign port: 179
> >
> > Enqueued packets for retransmit: 0, input: 0 mis-ordered: 0 (0 bytes)
> >
> > Event Timers (current time is 0xFAFAF384):
> > Timer Starts Wakeups Next
> > Retrans 5 0 0x0
> > TimeWait 0 0 0x0
> > AckHold 4 1 0x0
> > SendWnd 0 0 0x0
> > KeepAlive 0 0 0x0
> > GiveUp 0 0 0x0
> > PmtuAger 0 0 0x0
> > DeadWait 0 0 0x0
> >
> > iss: 4186393376 snduna: 4186393479 sndnxt: 4186393479 sndwnd: 16282
> > irs: 1908286013 rcvnxt: 1908286158 rcvwnd: 16240 delrcvwnd: 144
> >
> > SRTT: 165 ms, RTTO: 1410 ms, RTV: 1245 ms, KRTT: 0 ms
> > minRTT: 0 ms, maxRTT: 472 ms, ACK hold: 200 ms
> > Flags: higher precedence, nagle
> >
> > Datagrams (max data segment is 536 bytes):
> > Rcvd: 7 (out of order: 0), with data: 4, total data bytes: 144
> > Sent: 7 (retransmit: 0, fastretransmit: 0), with data: 4, total data
> > bytes: 102
> >
> > c7200.caravan.ru#sh ver
> > Cisco Internetwork Operating System Software
> > IOS (tm) 7200 Software (C7200-JS-M), Version 12.2(1a), RELEASE SOFTWARE
> > (fc1)
> > Copyright (c) 1986-2001 by cisco Systems, Inc.
> > Compiled Fri 25-May-01 20:19 by pwade
> > Image text-base: 0x60008960, data-base: 0x616B2000
> > -------------------------------------------------------------------
> >
> > Any ideas? Why my network is not advertised to 2.2.2.2 if 1.0.0.0/8 is
> > not exist (not received from IPS1) ??
> > I'll be very grateful for any advices.
> >
> > Thank you for advance.
> >
> >
>
>
This archive was generated by hypermail 2b29 : Sun Aug 04 2002 - 04:13:21 EDT