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Session problem.

examples20001
Level 1
Level 1

Hi,

I have a VPN session which is working good.

For some reason there was some trouble at some ISP between the two VPN peers and the packets are not passing to two VPN peers.

The ISP problem has been for more than 8 hrs, but my doubt is that, when I check the peer crypto session details, it is UP-ACTIVE now also.

Why the session is not going down once three keepalive packets are missed, and why not IPSec termination point not concludes that it has lot connectivity with its peer?

I have given the command:

crypto isakmp keepalive 30 periodic

crypto ipsec security-association lifetime seconds 86400

aaa#show cry session remote A.B.C.24 detail

Crypto session current status

Code: C - IKE Configuration mode, D - Dead Peer Detection

K - Keepalives, N - NAT-traversal, X - IKE Extended Authentication

Interface: GigabitEthernet0/1

Session status: UP-ACTIVE

Peer: A.B.C.24 port 500 fvrf: (none) ivrf: (none)

Desc: Tunnel toA.B.C.24 (AAA)

Phase1_id: A.B.C.24

IKE SA: local P.Q.R.1/500 remote A.B.C.24/500 Active

Capabilities:(none) connid:269 lifetime:21:53:23

IPSEC FLOW: permit ip 172.17.12.0/255.255.255.0 10.11.6.0/255.255.255.0

Active SAs: 2, origin: crypto map

Inbound: #pkts dec'ed 1254709 drop 1 life (KB/Sec) 4449894/78804

Outbound: #pkts enc'ed 1330421 drop 2989 life (KB/Sec) 4449877/78804

aaa#show cry isa sa

dst src state conn-id slot status

A.B.C.24 P.Q.R.1 QM_IDLE 269 0 ACTIVE

aaa#ping 10.11.6.18 source 172.17.12.11

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 10.11.6.18, timeout is 2 seconds:

Packet sent with a source address of 172.17.12.11

.....

Success rate is 0 percent (0/5)

aaa#

aaa#ping A.B.C.24

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to A.B.C.24, timeout is 2 seconds:

.....

Success rate is 0 percent (0/5)

aaa#

4 Replies 4

spremkumar
Level 9
Level 9

Hi

Can you post out the config of both the routers?

regds

Hi,

VPN is working good.

The problem is that the VPN session is not expiring, when three keepalive packets are missed and IPSec termination point is not concluding that it has lot connectivity with its peer.

Why is it so?

My end vpn router config details is below, other end vpn box is not cisco.

version 12.4

ip cef

ip sla monitor logging traps

ip sla monitor 21

type echo protocol ipIcmpEcho 10.11.6.10 source-interface GigabitEthernet0/0

ip sla monitor schedule 21 life forever start-time now

crypto logging session

crypto isakmp policy 2

encr 3des

authentication pre-share

group 2

crypto isakmp key xxxxxxxxxx address A.B.C.24 255.255.255.240 no-xauth

crypto isakmp invalid-spi-recovery

crypto isakmp keepalive 30 periodic

crypto isakmp nat keepalive 30

crypto isakmp peer address A.B.C.24

description Tunnel toA.B.C.24 ()

crypto ipsec security-association lifetime seconds 86400

crypto ipsec transform-set vpnset esp-3des esp-sha-hmac

crypto ipsec df-bit clear

no crypto ipsec nat-transparency udp-encaps

crypto map vpnmap1 redundancy replay-interval inbound 10 outbound 1000

crypto map vpnmap1 27 ipsec-isakmp

description Tunnel toA.B.C.24()

set peer A.B.C.24

set transform-set vpnset

match address 130

interface Null0

no ip unreachables

interface GigabitEthernet0/0

description LAN

ip address 172.17.12.11 255.255.255.0

ip access-group 100 in

no ip redirects

no ip unreachables

no ip proxy-arp

ip nbar protocol-discovery

ip flow ingress

ip flow egress

ip nat inside

ip virtual-reassembly

no ip route-cache cef

ip route-cache flow

ip tcp adjust-mss 1376

duplex auto

speed auto

no mop enabled

standby version 2

standby 10 ip 172.17.12.10

standby 10 timers 1 10

standby 10 priority 105

standby 10 preempt

standby 10 name vpn-in

standby 10 track GigabitEthernet0/1

standby 10 track GigabitEthernet0/0

interface GigabitEthernet0/1

description WAN

ip address P.Q.R.11 255.255.255.192

ip access-group 101 in

ip verify unicast reverse-path

no ip redirects

no ip unreachables

no ip proxy-arp

ip nat outside

ip virtual-reassembly

ip route-cache flow

duplex auto

speed auto

no mop enabled

standby version 2

standby 20 ip P.Q.R.1

standby 20 timers 1 10

standby 20 priority 105

standby 20 preempt

standby 20 name vpn-out

standby 20 track GigabitEthernet0/1

standby 20 track GigabitEthernet0/0

crypto map vpnmap1 redundancy vpn-out stateful

ip route 0.0.0.0 0.0.0.0 P.Q.R.1

ip route 10.11.6.0 255.255.255.0 GigabitEthernet0/1

ip nat Stateful id 20

redundancy vpn-out

mapping-id 20

as-queuing disable

protocol udp

ip nat pool nat-out-pool P.Q.R.11 P.Q.R.11 prefix-length 26

ip nat inside source route-map vpn_rmap1 pool nat-out-pool mapping-id 20 overload

logging trap debugging

access-list 100 deny ip P.Q.R.0 0.0.0.255 any

access-list 100 deny ip host 255.255.255.255 any

access-list 100 deny ip 127.0.0.0 0.255.255.255 any

access-list 100 permit ip any any

access-list 101 permit icmp any any

access-list 101 remark IPSec Rule

access-list 101 permit udp any P.Q.R.0 0.0.0.255 eq non500-isakmp

access-list 101 permit udp any P.Q.R.0 0.0.0.255 eq isakmp

access-list 101 permit esp any P.Q.R.0 0.0.0.255

access-list 101 permit ahp any P.Q.R.0 0.0.0.255

access-list 101 deny ip any any log

access-list 104 deny ip 172.17.12.0 0.0.0.255 172.16.0.0 0.15.255.255

access-list 104 permit ip 172.17.12.0 0.0.0.255 any

access-list 130 remark IPSec -

access-list 130 permit ip 172.17.12.0 0.0.0.255 10.11.6.0 0.0.0.255

route-map vpn_rmap1 permit 1

match ip address 104

end

crypto isakmp keepalive 30 periodic

crypto ipsec security-association lifetime seconds 86400

Your problem is above. The periodic command does not work correctly and is unreliable.

Go back to only "cry is keepalive 30" and it will be fine.

Hi,

Thank you very much for the reply.

Is there any bug in the command "crypto isakmp keepalive 30 periodic"?

Problem is that cisco never re-establishes the tunnel within the assigned lifetime 86400.

If the other end peer?s tunnel got broken within 86400 and it tries to re-establish the connection, Cisco is not re-establishing it and our network is down for so many hours, till Cisco automatically re-establish the connections after its lifetime 86400.

How to solve this problem?

Cisco doc says:

The IPSec Dead Peer Detection Periodic Message Option feature allows you to configure your router to query the liveliness of its Internet Key Exchange (IKE) peer at regular intervals. The benefit of this approach over the default approach (on-demand dead peer detection) is earlier detection of dead peers.

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