OpenBGP "state change OpenSent -> Active, reason: Connection closed" trouble

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To: <misc@...>
Date: Wednesday, January 16, 2008 - 9:17 am

Hello everybody.

I am setting up OpenBGP for the first time in replacement to Cisco.
However, I am having some troubles which I could not realize the
reason myself, so I

#macros
peer_gvt=200.139.89.37
peer_intelig=200.184.196.18
#peer_intelig=201.70.200.1

# Configuracao Global
AS 28660
router-id 201.87.224.253
# route-reflector 3381352702
log updates

#holdtime 180
#holdtime min 3

holdtime 4
holdtime min 3

#listen on <ip router>

#fib-update no
fib-update yes
#route-collector yes

#network 201.87.224.0/20 # full routing
network 201.87.224.0/23 # partial routing

# neighbors and peers

#group "peering AS4230" {
# remote-as 4230
# neighbor $peer1 {
# descr "ASN4230 Embratel"
# announce self
# tcp md5sig password 7890
# }
#}
group "peering GVT" {
remote-as 18881
neighbor $peer_gvt {
descr "GVT"
#multihop 2
#local-address <ip router twi>
#softreconfig in yes
depend on em1
#passive
holdtime 3
holdtime min 3
announce self # ebgp = self, ibgp = all - twi sera ebgp
}
}

group "peering Intelig" {
remote-as 17379
neighbor $peer_intelig {
descr "Intelig"
multihop 4
#local-address 201.70.200.2
#softreconfig in yes
#depend on em0
#passive
holdtime 3
holdtime min 3
announce self # ebgp = self, ibgp = all - twi sera ebgp
}
}

#
# Filtros
#

deny from any
allow from any prefixlen 8 - 24 # publicacao de 8 a 24 bits, nem mais nem menos

deny from any prefix 0.0.0.0/0 # nao aceita publicacao de rota padrao

# Redes as quais nunca permitiremos publicacao de rotas
deny from any prefix 10.0.0.0/8 prefixlen >= 8
deny from any prefix 172.16.0.0/12 prefixlen >= 12
deny from any prefix 192.168.0.0/16 prefixlen &g...

To: <misc@...>
Date: Wednesday, January 16, 2008 - 10:14 am

tcp connection has been established and we sent our OPEN message to the

the neighbor closed the tcp connection.
why?
we cannot know.
there should be a message in the neighbor's log.

--
Henning Brauer, hb@bsws.de, henning@openbsd.org
BS Web Services, http://bsws.de
Full-Service ISP - Secure Hosting, Mail and DNS Services
Dedicated Servers, Rootservers, Application Hosting - Hamburg & Amsterdam

To: Eduardo Meyer <dudu.meyer@...>
Cc: <misc@...>
Date: Wednesday, January 16, 2008 - 9:43 am

is this the correct local-address?

"tcpdump -nvvs1500 -i<interface> port 179" might give more clues.

To: Eduardo Meyer <dudu.meyer@...>, <misc@...>
Date: Wednesday, January 16, 2008 - 10:33 am

I have lowered holdtime for testing purposes only. With default value
the behavior is the same. I have just forced local-address to another
one, with "local-address 201.70.200.2" but still the same.

Here is the tcpdum output

22:39:40.566835 IP (tos 0xc0, ttl 4, id 9918, offset 0, flags [DF],
proto: TCP (6), length: 52) 201.87.225.16.61409 > 200.184.196.18.179:
F, cksum 0x375a (incorrect (-> 0x3ca1), 990673835:990673835(0) ack
1878726869 win 33304 <nop,nop,timestamp 105680141 22526977>
22:39:43.925328 IP (tos 0xc0, ttl 4, id 9930, offset 0, flags [DF],
proto: TCP (6), length: 64) 201.87.225.16.57856 > 200.184.196.18.179:
S, cksum 0x3766 (incorrect (-> 0xdc9c), 2171084445:2171084445(0) win
65535 <mss 1460,nop,wscale 1,nop,nop,timestamp 105683499 0,sackOK,eol>
22:39:43.933442 IP (tos 0xc0, ttl 63, id 2913, offset 0, flags [DF],
proto: TCP (6), length: 64) 200.184.196.18.179 > 201.87.225.16.57856:
S, cksum 0xb4d4 (correct), 1446395664:1446395664(0) ack 2171084446 win
16384 <mss 1460,nop,wscale 0,nop,nop,timestamp 22565145
105683499,sackOK,eol>
22:39:43.933508 IP (tos 0xc0, ttl 4, id 9933, offset 0, flags [DF],
proto: TCP (6), length: 52) 201.87.225.16.57856 > 200.184.196.18.179:
., cksum 0x375a (incorrect (-> 0xb27e), 1:1(0) ack 1 win 33304
<nop,nop,timestamp 105683507 22565145>
22:39:43.933609 IP (tos 0xc0, ttl 4, id 9934, offset 0, flags [DF],
proto: TCP (6), length: 101) 201.87.225.16.57856 > 200.184.196.18.179:
P, cksum 0x378b (incorrect (-> 0x69a3), 1:50(49) ack 1 win 33304
<nop,nop,timestamp 105683507 22565145>: BGP, length: 49
Open Message (1), length: 49
Version 4, my AS 28660, Holdtime 90s, ID 201.87.224.253
Optional parameters, length: 20
Option Capabilities Advertisement (2), length: 6
Multiprotocol Extensions (1), length: 4
AFI IPv4 (1), SAFI Unicast (1)
0x0000: 0001 0001
Option Capabilities Advertisement...

To: Eduardo Meyer <dudu.meyer@...>
Cc: <misc@...>
Date: Wednesday, January 16, 2008 - 11:15 am

that doesn't look like openbsd, ours is easy to read ;-)

the peer just closes the connection on receipt of the Open.
you can either try experimenting with disabling some options
(announce ipv6 none, announce capabilities no) or better,
talk to your peer and see what they have logged.

22:39:43.933609 IP (tos 0xc0, ttl 4, id 9934, offset 0, flags [DF],
proto: TCP (6), length: 101) 201.87.225.16.57856 > 200.184.196.18.179:
P, cksum 0x378b (incorrect (-> 0x69a3), 1:50(49) ack 1 win 33304
<nop,nop,timestamp 105683507 22565145>: BGP, length: 49
Open Message (1), length: 49
Version 4, my AS 28660, Holdtime 90s, ID 201.87.224.253
Optional parameters, length: 20
Option Capabilities Advertisement (2), length: 6
Multiprotocol Extensions (1), length: 4
AFI IPv4 (1), SAFI Unicast (1)
0x0000: 0001 0001
Option Capabilities Advertisement (2), length: 2
Route Refresh (2), length: 0
Option Capabilities Advertisement (2), length: 6
Graceful Restart (64), length: 4
Restart Flags: [R], Restart Time 0s
0x0000: 8000 0000
22:39:43.939183 IP (tos 0xc0, ttl 63, id 2914, offset 0, flags [DF],
proto: TCP (6), length: 52) 200.184.196.18.179 > 201.87.225.16.57856: F,
cksum 0xf07e (correct), 1:1(0) ack 50 win 17376 <nop,nop,timestamp
22565151 105683507>

To: Eduardo Meyer <dudu.meyer@...>, <misc@...>
Date: Monday, January 21, 2008 - 9:21 am

Hello,

This follow-up is to thank you all who replied and mention the
solution (what is good for the history). I forced binding to the
correct IP address declaring neighbor's local address, and added a
static route to the box, instead of using the default one, although
they were nexthoping to the same address.

Finally I removed the "passive" keyword. Now its OK with the first BGP
neighbor, I will setup the second tomorrow morning but probably there
wont be any other problem.

Thank you all and thanks for OpenBGP. Way simple, functional and much
better/clearer than cisco.

--
===========
Eduardo Meyer

To: Eduardo Meyer <dudu.meyer@...>
Cc: <misc@...>
Date: Wednesday, January 16, 2008 - 9:44 am

Previous thread: Devenez le photographe de tous vous produits by No on Wednesday, January 16, 2008 - 9:00 am. (1 message)

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