BGP Adj Flapping-Cisco887 ADSL&GRE

Unanswered Question
Sep 23rd, 2010

Hello everyone,

We're deploying a brand new network for a customer. We've got problems on several ADSL links: we're having repetitive BGP Adj connect/disconnect problems.
On these links I've identified around 2% packet loss....with a scheme like this one: !!!!!!.....!!!!!
Provider confirmed a 2% ATM cells loss on the links but they offer no service guarantee for that...
We use C887 routers with IOS 15.1.1. ADSL+GRE. Provider use Huawei DSLAMs.

Is there any "config solution" to that problem? Big chance we'll get packet losses on these ADSL links from time to time... I can't afford the bgp sessions to flap like this...
Do you think I should increase the hellos value with the following command line:  neighbor ip_address advertisement-interval seconds ?
If so, I know that I have to enter the same values on both sides of the session (C887 <------> ASR1002)....but I don't want this to apply to all my different BGP sessions on the core router (ASR-1002F).....Below part of the conf and part of a debug.
Thanks in advance for your help!

K

interface Loopback1
ip address 172.27.10.56 255.255.255.255
!
interface Tunnel10
ip vrf forwarding VRFA
ip address 10.40.2.114 255.255.255.252
ip pim sparse-mode
ip tcp adjust-mss 1300
tunnel source 172.27.10.56
tunnel destination 172.27.0.56
!
interface ATM0
no ip address
  atm ilmi-keepalive
pvc 8/35
  encapsulation aal5mux ppp dialer
  dialer pool-member 1

interface Dialer0
ip address negotiated
encapsulation ppp
dialer pool 1
dialer-group 1
ppp authentication chap callin
ppp chap hostname [email protected]
ppp chap password xxxxxxxxxxxx
no cdp enable
!
router bgp 65001
template peer-session AS65000
  remote-as 65000
  password xxxxxxxxx
  ebgp-multihop 3
  update-source Dialer0
  timers 5 15
exit-peer-session
!
template peer-session TEST-AS65000
  remote-as 65000
  password xxxxxxxxxxxxxx
  ebgp-multihop 3
  update-source Tunnel10
  timers 5 15
exit-peer-session
!
bgp log-neighbor-changes
neighbor 172.25.254.254 inherit peer-session AS65000
!
address-family ipv4
  no synchronization
  redistribute connected route-map CON-IN-BGP-GLOBAL
  neighbor 172.25.254.254 activate
  no auto-summary
exit-address-family
!
address-family ipv4 vrf VRFA
  no synchronization
  network 172.30.208.16 mask 255.255.255.240
  neighbor 10.40.2.113 inherit peer-session TEST-AS65000
  neighbor 10.40.2.113 activate
exit-address-family
============================
Sep 23 10:57:51.069: BGP: ses global 172.25.254.254 (0x860FF0EC:1) Keep alive timer fired.
.Sep 23 10:57:51.069: BGP: 172.25.254.254 KEEPALIVE requested (bgp_keepalive_timer_expired)
.Sep 23 10:57:51.069: BGP: ses global 172.25.254.254 (0x860FF0EC:1) service keepalive IO request.
.Sep 23 10:57:51.069: BGP: 172.25.254.254 KEEPALIVE write request serviced in BGP_IO
.Sep 23 10:57:52.093: %BGP-5-ADJCHANGE: neighbor 172.25.254.254 Down BGP Notification sent
.Sep 23 10:57:52.093: %BGP-3-NOTIFICATION: sent to neighbor 172.25.254.254 4/0 (hold time expired) 0 bytes
.Sep 23 10:57:52.093: %BGP_SESSION-5-ADJCHANGE: neighbor 172.25.254.254 IPv4 Unicast topology base removed from session  BGP Notification sent
.Sep 23 10:58:00.641: BGP: 172.25.254.254 passive KEEPALIVE write request serviced in BGP_IO
.Sep 23 10:58:00.641: BGP: 172.25.254.254 passive service 2 read request in BGP_IO
.Sep 23 10:58:00.641: BGP: 172.25.254.254 passive service 2 read request in BGP_IO
.Sep 23 10:58:00.641: BGP: 172.25.254.254 passive KEEPALIVE requested (rcv_open)
.Sep 23 10:58:00.641: BGP: ses global 172.25.254.254 (0x860FF0EC:0) pas service keepalive IO request.
.Sep 23 10:58:00.641: BGP: 172.25.254.254 passive KEEPALIVE write request serviced in BGP_IO
.Sep 23 10:58:00.693: BGP: 172.25.254.254 passive KEEPALIVE write request serviced in BGP_IO

I have this problem too.
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