07-06-2016 06:21 AM - edited 03-05-2019 04:22 AM
Hello All,
I'm having a problem with my carrier.
My router is showing short BGP flaps every days but carrier router installed at my office is not showing any down ( this is a L2 connection and I have BGP directly with remote site ).
Logs of 1st July is due to a change port configuration, so it's not a fault.
What I need is give evidence to Carrier that their line is causing my BGP flapping every day.
Thanks in advance to all.
RGDS Massimo
My router logs:
ion sent
Jul 3 16:24:07: %BGP-5-ADJCHANGE: neighbor 57.21.26.29 Up
Jul 6 02:02:22: %BGP-3-NOTIFICATION: received from neighbor 57.21.26.29 4/0 (hold time expired) 0 bytes
Jul 6 02:02:22: %BGP-5-ADJCHANGE: neighbor 57.21.26.29 Down BGP Notification received
Jul 6 02:02:22: %BGP_SESSION-5-ADJCHANGE: neighbor 57.21.26.29 IPv4 Unicast topology base removed from session BGP Notification received
Jul 6 02:02:46: %BGP-5-ADJCHANGE: neighbor 57.21.26.29 Up
Jul 6 02:06:52: %BGP-5-ADJCHANGE: neighbor 57.21.26.29 Down BGP Notification sent
Jul 6 02:06:52: %BGP-3-NOTIFICATION: sent to neighbor 57.21.26.29 4/0 (hold time expired) 0 bytes
Jul 6 02:06:52: %BGP_SESSION-5-ADJCHANGE: neighbor 57.21.26.29 IPv4 Unicast topology base removed from session BGP Notification sent
Jul 6 02:07:01: %BGP-5-ADJCHANGE: neighbor 57.21.26.29 Up
Carrier's Router Logs:
*Jul 1 13:04:32.491: %LINK-3-UPDOWN: Interface GigabitEthernet0/1, changed state to down
*Jul 1 13:04:33.491: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/1, changed state to down
*Jul 1 13:04:35.775: %LINK-3-UPDOWN: Interface GigabitEthernet0/1, changed state to up
*Jul 1 13:04:36.775: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/1, changed state to up
*Jul 1 13:04:42.947: %SYS-5-SCHEDULED_RELOAD_CANCELLED: Scheduled reload cancelled at 13:04:42 UTC Fri Jul 1 2016
07-06-2016 06:38 AM
Hello Massimo
Could you please try to ping the remote IP with the size of the MTU and df-bit set.
ping 57.21.26.29 size 1500 df-bit repeat 100 (assuming your interface MTU is 1500)
if the ping doesn't go through, then the problem is with your MTU settings in the path.
also, is your BGP flapping every few minutes?
07-06-2016 06:50 AM
Hello Vinit,
thanks for your feedback, BGP is flapping randomically every 1 or 2 days.
But on same days is flapping more frequently
Jun 29 03:12:12: %BGP-5-ADJCHANGE: neighbor 57.21.26.29 Up
Jun 29 03:17:27: %BGP-5-ADJCHANGE: neighbor 57.21.26.29 Down BGP Notification sent
Jun 29 03:17:27: %BGP-3-NOTIFICATION: sent to neighbor 57.21.26.29 4/0 (hold time expired) 0 bytes
Jun 29 03:17:27: %BGP_SESSION-5-ADJCHANGE: neighbor 57.21.26.29 IPv4 Unicast topology base removed from session BGP Notification sent
Jun 29 03:17:51: %BGP-5-ADJCHANGE: neighbor 57.21.26.29 Up
Jun 29 03:34:25: %BGP-5-ADJCHANGE: neighbor 57.21.26.29 Down BGP Notification sent
Jun 29 03:34:25: %BGP-3-NOTIFICATION: sent to neighbor 57.21.26.29 4/0 (hold time expired) 0 bytes
Jun 29 03:34:25: %BGP_SESSION-5-ADJCHANGE: neighbor 57.21.26.29 IPv4 Unicast topology base removed from session BGP Notification sent
Jun 29 03:34:56: %BGP-5-ADJCHANGE: neighbor 57.21.26.29 Up
Jun 29 03:37:58: %BGP-5-ADJCHANGE: neighbor 57.21.26.29 Down BGP Notification sent
Jun 29 03:37:58: %BGP-3-NOTIFICATION: sent to neighbor 57.21.26.29 4/0 (hold time expired) 0 bytes
Jun 29 03:37:58: %BGP_SESSION-5-ADJCHANGE: neighbor 57.21.26.29 IPv4 Unicast topology base removed from session BGP Notification sent
Jun 29 03:38:10: %BGP-5-ADJCHANGE: neighbor 57.21.26.29 Up
Jun 29 03:42:26: %BGP-5-ADJCHANGE: neighbor 57.21.26.29 Down BGP Notification sent
Jun 29 03:42:26: %BGP-3-NOTIFICATION: sent to neighbor 57.21.26.29 4/0 (hold time expired) 0 bytes
Jun 29 03:42:26: %BGP_SESSION-5-ADJCHANGE: neighbor 57.21.26.29 IPv4 Unicast topology base removed from session BGP Notification sent
Jun 29 03:42:37: %BGP-5-ADJCHANGE: neighbor 57.21.26.29 Up
Jun 29 03:50:26: %BGP-5-ADJCHANGE: neighbor 57.21.26.29 Down BGP Notification sent
Jun 29 03:50:26: %BGP-3-NOTIFICATION: sent to neighbor 57.21.26.29 4/0 (hold time expired) 0 bytes
Jun 29 03:50:26: %BGP_SESSION-5-ADJCHANGE: neighbor 57.21.26.29 IPv4 Unicast topology base removed from session BGP Notification sent
Jun 29 03:50:36: %BGP-5-ADJCHANGE: neighbor 57.21.26.29 Up
Jun 29 13:17:21: %BGP-5-ADJCHANGE: neighbor 57.21.26.29 Down BGP Notification sent
Jun 29 13:17:21: %BGP-3-NOTIFICATION: sent to neighbor 57.21.26.29 4/0 (hold time expired) 0 bytes
Jun 29 13:17:21: %BGP_SESSION-5-ADJCHANGE: neighbor 57.21.26.29 IPv4 Unicast topology base removed from session BGP Notification sent
Jun 29 13:17:29: %BGP-5-ADJCHANGE: neighbor 57.21.26.29 Up
Jun 29 13:58:09: %BGP-5-ADJCHANGE: neighbor 57.21.26.29 Down BGP Notification sent
Jun 29 13:58:09: %BGP-3-NOTIFICATION: sent to neighbor 57.21.26.29 4/0 (hold time expired) 0 bytes
Jun 29 13:58:09: %BGP_SESSION-5-ADJCHANGE: neighbor 57.21.26.29 IPv4 Unicast topology base removed from session BGP Notification sent
Jun 29 13:58:29: %BGP-3-NOTIFICATION: received from neighbor 57.21.26.29 active 2/8 (no supported AFI/SAFI) 3 bytes 000000
Jun 29 13:58:29: %BGP_SESSION-5-ADJCHANGE: neighbor 57.21.26.29 IPv4 Unicast topology base removed from session BGP Notification received
Jun 29 13:58:32: %BGP-5-ADJCHANGE: neighbor 57.21.26.29 Up
Jun 29 14:02:01: %BGP-5-ADJCHANGE: neighbor 57.21.26.29 Down BGP Notification sent
Jun 29 14:02:01: %BGP-3-NOTIFICATION: sent to neighbor 57.21.26.29 4/0 (hold time expired) 0 bytes
Jun 29 14:02:01: %BGP_SESSION-5-ADJCHANGE: neighbor 57.21.26.29 IPv4 Unicast topology base removed from session BGP Notification sent
Jun 29 14:02:12: %BGP-5-ADJCHANGE: neighbor 57.21.26.29 Up
Jun 29 14:03:34: %BGP-5-ADJCHANGE: neighbor 57.21.26.29 Down BGP Notification sent
Jun 29 14:03:34: %BGP-3-NOTIFICATION: sent to neighbor 57.21.26.29 4/0 (hold time expired) 0 bytes
Jun 29 14:03:34: %BGP_SESSION-5-ADJCHANGE: neighbor 57.21.26.29 IPv4 Unicast topology base removed from session BGP Notification sent
Jun 29 14:03:48: %BGP-5-ADJCHANGE: neighbor 57.21.26.29 Up
Jun 29 14:07:35: %BGP-5-ADJCHANGE: neighbor 57.21.26.29 Down BGP Notification sent
Jun 29 14:07:35: %BGP-3-NOTIFICATION: sent to neighbor 57.21.26.29 4/0 (hold time expired) 0 bytes
Jun 29 14:07:35: %BGP_SESSION-5-ADJCHANGE: neighbor 57.21.26.29 IPv4 Unicast topology base removed from session BGP Notification sent
Jun 29 14:08:08: %BGP-5-ADJCHANGE: neighbor 57.21.26.29 Up
Jun 29 14:29:37: %BGP-5-ADJCHANGE: neighbor 57.21.26.29 Down BGP Notification sent
Jun 29 14:29:37: %BGP-3-NOTIFICATION: sent to neighbor 57.21.26.29 4/0 (hold time expired) 0 bytes
Jun 29 14:29:37: %BGP_SESSION-5-ADJCHANGE: neighbor 57.21.26.29 IPv4 Unicast topology base removed from session BGP Notification sent
Jun 29 14:30:24: %BGP-5-ADJCHANGE: neighbor 57.21.26.29 Up
Jul 1 11:53:24: %BGP-5-ADJCHANGE: neighbor 57.21.26.29 Down Interface flap
Jul 1 11:53:24: %BGP_SESSION-5-ADJCHANGE: neighbor 57.21.26.29 IPv4 Unicast topology base removed from session Interface flap
Jul 1 11:53:33: %BGP-5-ADJCHANGE: neighbor 57.21.26.29 Up
Jul 1 13:38:12: %BGP-5-ADJCHANGE: neighbor 57.21.26.29 Down Interface flap
Jul 1 13:38:12: %BGP_SESSION-5-ADJCHANGE: neighbor 57.21.26.29 IPv4 Unicast topology base removed from session Interface flap
Jul 1 13:38:28: %BGP-5-ADJCHANGE: neighbor 57.21.26.29 Up
Jul 3 08:17:42: %BGP-5-ADJCHANGE: neighbor 57.21.26.29 Down BGP Notification sent
Jul 3 08:17:42: %BGP-3-NOTIFICATION: sent to neighbor 57.21.26.29 4/0 (hold time expired) 0 bytes
Jul 3 08:17:42: %BGP_SESSION-5-ADJCHANGE: neighbor 57.21.26.29 IPv4 Unicast topology base removed from session BGP Notification sent
Jul 3 08:21:59: %BGP-5-ADJCHANGE: neighbor 57.21.26.29 Up
Jul 3 16:19:34: %BGP-5-ADJCHANGE: neighbor 57.21.26.29 Down BGP Notification sent
Jul 3 16:19:34: %BGP-3-NOTIFICATION: sent to neighbor 57.21.26.29 4/0 (hold time expired) 0 bytes
Jul 3 16:19:34: %BGP_SESSION-5-ADJCHANGE: neighbor 57.21.26.29 IPv4 Unicast topology base removed from session BGP Notification sent
Jul 3 16:24:07: %BGP-5-ADJCHANGE: neighbor 57.21.26.29 Up
Jul 6 02:02:22: %BGP-3-NOTIFICATION: received from neighbor 57.21.26.29 4/0 (hold time expired) 0 bytes
Jul 6 02:02:22: %BGP-5-ADJCHANGE: neighbor 57.21.26.29 Down BGP Notification received
Jul 6 02:02:22: %BGP_SESSION-5-ADJCHANGE: neighbor 57.21.26.29 IPv4 Unicast topology base removed from session BGP Notification received
Jul 6 02:02:46: %BGP-5-ADJCHANGE: neighbor 57.21.26.29 Up
Jul 6 02:06:52: %BGP-5-ADJCHANGE: neighbor 57.21.26.29 Down BGP Notification sent
Jul 6 02:06:52: %BGP-3-NOTIFICATION: sent to neighbor 57.21.26.29 4/0 (hold time expired) 0 bytes
Jul 6 02:06:52: %BGP_SESSION-5-ADJCHANGE: neighbor 57.21.26.29 IPv4 Unicast topology base removed from session BGP Notification sent
Jul 6 02:07:01: %BGP-5-ADJCHANGE: neighbor 57.21.26.29 Up
07-06-2016 06:55 AM
Thanks for the reply. Could you please share the below logs:
- show version
- show run interface <int-num> // Interface where the provider is connected
- show inter <int-num>
Since when are you seeing the problem?
Regards
Vinit
07-06-2016 06:59 AM
Hi,
do you need physical or logical interface?
RGDS
MDS
02-23-2017 01:07 PM
Hi all,
I have the same problem !
CE(CISCO2911) -> PE(CISCO7606s) directly connected with two interfaces GigabitEthernet, and value MTU configured 1550 both directions.
Someone have idea how can solved this possible problem ?
regards
Sérgio Garcia
07-06-2016 07:14 AM
Hello Vinit,
problem is on going for last 2 months.
Here below info you required,
thanks a lot for support
Massimo
XXXX#sh vers
Cisco IOS Software, C2900 Software (C2900-UNIVERSALK9-M), Version 15.2(4)M8, RELEASE SOFTWARE (fc1)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2015 by Cisco Systems, Inc.
Compiled Thu 02-Apr-15 14:11 by prod_rel_team
ROM: System Bootstrap, Version 15.0(1r)M15, RELEASE SOFTWARE (fc1)
pmpm198 uptime is 6 weeks, 4 days, 2 hours, 13 minutes
System returned to ROM by reload
System restarted at 13:46:08 GMT+2 Sat May 21 2016
System image file is "flash:c2900-universalk9-mz.SPA.152-4.M8"
Last reload type: Normal Reload
Last reload reason: power-on
This product contains cryptographic features and is subject to United
States and local country laws governing import, export, transfer and
use. Delivery of Cisco cryptographic products does not imply
third-party authority to import, export, distribute or use encryption.
Importers, exporters, distributors and users are responsible for
compliance with U.S. and local country laws. By using this product you
agree to comply with applicable laws and regulations. If you are unable
to comply with U.S. and local laws, return this product immediately.
A summary of U.S. laws governing Cisco cryptographic products may be found at:
http://www.cisco.com/wwl/export/crypto/tool/stqrg.html
If you require further assistance please contact us by sending email to
export@cisco.com.
Cisco CISCO2921/K9 (revision 1.0) with 479232K/45056K bytes of memory.
Processor board ID FCZ174160L9
3 Gigabit Ethernet interfaces
1 terminal line
1 Virtual Private Network (VPN) Module
DRAM configuration is 64 bits wide with parity enabled.
255K bytes of non-volatile configuration memory.
250880K bytes of ATA System CompactFlash 0 (Read/Write)
License Info:
License UDI:
-------------------------------------------------
Device# PID SN
-------------------------------------------------
*0 CISCO2921/K9 FCZ174160L9
Technology Package License Information for Module:'c2900'
-----------------------------------------------------------------
Technology Technology-package Technology-package
Current Type Next reboot
------------------------------------------------------------------
ipbase ipbasek9 Permanent ipbasek9
security securityk9 Permanent securityk9
uc uck9 Permanent uck9
data datak9 RightToUse datak9
Configuration register is 0x2102
XXXX#sh run int Gi0/1
Building configuration...
Current configuration : 231 bytes
!
interface GigabitEthernet0/1
description --- Carrier=CMC NETWORKS , Offer=Junxion EVPL Gold - FastE
bandwidth 10000
no ip address
no ip redirects
no ip proxy-arp
load-interval 30
duplex full
speed 100
no cdp enable
end
XXXX#sh run int Gi0/1.456
Building configuration...
Current configuration : 315 bytes
!
interface GigabitEthernet0/1.456
description To bjnb813 - Gi7/1/1.456 - 10000K
bandwidth 10000
encapsulation dot1Q 456
ip address 57.21.26.30 255.255.255.252
no ip redirects
no ip proxy-arp
ip flow ingress
ip flow egress
service-policy input COUNT-IN
service-policy output COS-OUT-SHAPED-Gi0/1.456
end
XXXX#sh int Gi0/1
GigabitEthernet0/1 is up, line protocol is up
Hardware is CN Gigabit Ethernet, address is c067.af62.d811 (bia c067.af62.d811)
Description: --- Carrier=CMC NETWORKS , Offer=Junxion EVPL Gold - FastE
MTU 1500 bytes, BW 10000 Kbit/sec, DLY 100 usec,
reliability 255/255, txload 29/255, rxload 23/255
Encapsulation 802.1Q Virtual LAN, Vlan ID 1., loopback not set
Keepalive set (10 sec)
Full Duplex, 100Mbps, media type is RJ45
output flow-control is unsupported, input flow-control is unsupported
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:00, output 00:00:00, output hang never
Last clearing of "show interface" counters 5d00h
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 28
Queueing strategy: Class-based queueing
Output queue: 0/1000/28 (size/max total/drops)
30 second input rate 915000 bits/sec, 377 packets/sec
30 second output rate 1150000 bits/sec, 380 packets/sec
69810661 packets input, 1174635334 bytes, 0 no buffer
Received 8015 broadcasts (0 IP multicasts)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 8015 multicast, 0 pause input
62448383 packets output, 1023681974 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
8015 unknown protocol drops
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier, 0 pause output
0 output buffer failures, 0 output buffers swapped out
XXXX#sh int Gi0/1.456
GigabitEthernet0/1.456 is up, line protocol is up
Hardware is CN Gigabit Ethernet, address is c067.af62.d811 (bia c067.af62.d811)
Description: To bjnb813 - Gi7/1/1.456 - 10000K
Internet address is 57.21.26.30/30
MTU 1500 bytes, BW 10000 Kbit/sec, DLY 100 usec,
reliability 255/255, txload 28/255, rxload 25/255
Encapsulation 802.1Q Virtual LAN, Vlan ID 456.
ARP type: ARPA, ARP Timeout 04:00:00
Keepalive set (10 sec)
Last clearing of "show interface" counters never
07-06-2016 07:35 AM
I dont see any drops on the interface that could be of concern. I do see that the router was rebooted 1.5 months ago. (6 weeks). Was the problem seen even before the reload.
Since this is a sub-interface, is there a switch in the middle as well that you manage or is it managed by provider?
please do share "show run | sec router bgp"
Regards
Vinit
07-06-2016 07:46 AM
Hi,
the problem was on going also before the reboot.
Here below the command
XXXX#show run | sec router bgp
router bgp 65000
bgp log-neighbor-changes
timers bgp 15 45
neighbor 57.21.26.29 remote-as 13879
neighbor 57.21.26.29 description --- PE XXXXX
!
address-family ipv4
network 10.185.160.56 mask 255.255.255.252
redistribute eigrp 64603 route-map EIGRP2BGP
neighbor 57.21.26.29 activate
neighbor 57.21.26.29 send-community
neighbor 57.21.26.29 route-map BGP-TAGGING-OUT out
exit-address-family
XXXX#
RGDS Massimo
07-06-2016 06:53 AM
Hello Vinit,
ping is working fine, no MTU size
***************************
pmpm198#ping 57.21.26.29 size 1500 df-bit repeat 100
Type escape sequence to abort.
Sending 100, 1500-byte ICMP Echos to 57.21.26.29, timeout is 2 seconds:
Packet sent with the DF bit set
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Success rate is 100 percent (100/100), round-trip min/avg/max = 24/26/32 ms
pmpm198#
*******************************
RGDS Massimo
03-30-2022 08:48 AM
In my own case, the issue was caused by a BGP session that was configured on the local router but the remote peer was not yet configured.
Immediately after the remote peer was set up, the flapping stop.
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