Re: ASA VPN peer failover timings

darenv · ‎06-14-2013

Hi

I have a lab config with two "data centre" firewalls and a "remote site" firewall. The remote site has a crypto map defined with two peer addresses. If the firewall in DC1 goes down, the remote site connects to the firewall in DC2 successfully and connectivity is restored (as DC1 and DC2 are connected together at the back end).

The failover process appears to be:

1) DC1 firewall fails

2) Remote site detects failure using DPD (approx 15-20 seconds - after 10 seconds of "silence", three DPD retries at 2 seconds apart)

3) Remote site tears down SAs over the tunnel to DC1

4) Interesting traffic arrives at remote site firewall, which looks at its crypto map config and attempts to initiate a tunnel to DC1

5) This eventually times out (approx 30 seconds) then the remote site firewall tries its backup peer which establishes immediately and connectivity is restored.

My question is ... is there a way I can either shorten the timeout value in 4) or to force the remote site firewall to not try DC1 again after it has failed, but to go straight to DC2? Basically, I want to be sure I can fail over in as short a time as possible when we have a site failure.

Any thoughts welcome!

Cheers, Daren.

darenv · ‎06-18-2013

Just as a further note - I have the logs or a 'debug crypo isakmp' on the remote site firewall which clearly show that the DPD doesn't mark the peer as dead, only tears down its SAs when it detects it is no longer there:

Jun 18 2013 00:52:46: %ASA-5-111008: User 'enable_15' executed the 'clear logging buffer' command.

Jun 18 2013 00:54:37: %ASA-3-713123: Group = 1.1.1.1, IP = 1.1.1.1, IKE lost contact with remote peer, deleting connection (keepalive type: DPD)

Jun 18 2013 00:54:37: %ASA-5-713259: Group = 1.1.1.1, IP = 1.1.1.1, Session is being torn down. Reason: Lost Service

Jun 18 2013 00:54:37: %ASA-4-113019: Group = 1.1.1.1, Username = 1.1.1.1, IP = 1.1.1.1, Session disconnected. Session Type: IPsec, Duration: 0h:03m:00s, Bytes xmt: 480192, Bytes rcv: 478992, Reason: Lost Service

Jun 18 2013 00:54:37: %ASA-5-713041: IP = 1.1.1.1, IKE Initiator: New Phase 1, Intf OUTSIDE, IKE Peer 1.1.1.1 local Proxy Address 10.233.224.4, remote Proxy Address 1.1.1.1, Crypto map (OUTSIDE-MAP)

Jun 18 2013 00:54:39: %ASA-3-713042: IKE Initiator unable to find policy: Intf INSIDE-TRANSIT, Src: 10.60.1.1, Dst: 10.250.1.1

Jun 18 2013 00:54:41: %ASA-3-713042: IKE Initiator unable to find policy: Intf INSIDE-TRANSIT, Src: 10.60.1.1, Dst: 10.250.1.1

Jun 18 2013 00:54:43: %ASA-3-713042: IKE Initiator unable to find policy: Intf INSIDE-TRANSIT, Src: 10.60.1.1, Dst: 10.250.1.1

Jun 18 2013 00:54:45: %ASA-3-713042: IKE Initiator unable to find policy: Intf INSIDE-TRANSIT, Src: 10.60.1.1, Dst: 10.250.1.1

Jun 18 2013 00:54:47: %ASA-3-713042: IKE Initiator unable to find policy: Intf INSIDE-TRANSIT, Src: 10.60.1.1, Dst: 10.250.1.1

Jun 18 2013 00:54:48: %ASA-3-713042: IKE Initiator unable to find policy: Intf INSIDE-TRANSIT, Src: 10.60.1.1, Dst: 10.250.1.1

Jun 18 2013 00:54:49: %ASA-3-713042: IKE Initiator unable to find policy: Intf INSIDE-TRANSIT, Src: 10.60.1.1, Dst: 10.250.1.1

Jun 18 2013 00:54:51: %ASA-3-713042: IKE Initiator unable to find policy: Intf INSIDE-TRANSIT, Src: 10.60.1.1, Dst: 10.250.1.1

Jun 18 2013 00:54:53: %ASA-3-713042: IKE Initiator unable to find policy: Intf INSIDE-TRANSIT, Src: 10.60.1.1, Dst: 10.250.1.1

Jun 18 2013 00:54:55: %ASA-3-713042: IKE Initiator unable to find policy: Intf INSIDE-TRANSIT, Src: 10.60.1.1, Dst: 10.250.1.1

Jun 18 2013 00:54:57: %ASA-3-713042: IKE Initiator unable to find policy: Intf INSIDE-TRANSIT, Src: 10.60.1.1, Dst: 10.250.1.1

Jun 18 2013 00:54:59: %ASA-3-713042: IKE Initiator unable to find policy: Intf INSIDE-TRANSIT, Src: 10.60.1.1, Dst: 10.250.1.1

Jun 18 2013 00:55:01: %ASA-3-713042: IKE Initiator unable to find policy: Intf INSIDE-TRANSIT, Src: 10.60.1.1, Dst: 10.250.1.1

Jun 18 2013 00:55:03: %ASA-3-713042: IKE Initiator unable to find policy: Intf INSIDE-TRANSIT, Src: 10.60.1.1, Dst: 10.250.1.1

Jun 18 2013 00:55:05: %ASA-3-713042: IKE Initiator unable to find policy: Intf INSIDE-TRANSIT, Src: 10.60.1.1, Dst: 10.250.1.1

Jun 18 2013 00:55:07: %ASA-3-713042: IKE Initiator unable to find policy: Intf INSIDE-TRANSIT, Src: 10.60.1.1, Dst: 10.250.1.1

Jun 18 2013 00:55:09: %ASA-5-713041: IP = 2.2.2.2, IKE Initiator: New Phase 1, Intf OUTSIDE, IKE Peer 2.2.2.2 local Proxy Address 10.233.224.4, remote Proxy Address 2.2.2.2, Crypto map (OUTSIDE-MAP)

Jun 18 2013 00:55:09: %ASA-5-713119: Group = 2.2.2.2, IP = 2.2.2.2, PHASE 1 COMPLETED

Jun 18 2013 00:55:09: %ASA-5-713049: Group = 2.2.2.2, IP = 2.2.2.2, Security negotiation complete for LAN-to-LAN Group (2.2.2.2) Initiator, Inbound SPI = 0xd21ad657, Outbound SPI = 0xd7d9c25a

Jun 18 2013 00:55:09: %ASA-5-713120: Group = 2.2.2.2, IP = 2.2.2.2, PHASE 2 COMPLETED (msgid=1949f878)

Jun 18 2013 00:55:09: %ASA-5-713041: Group = 2.2.2.2, IP = 2.2.2.2, IKE Initiator: New Phase 2, Intf INSIDE-TRANSIT, IKE Peer 2.2.2.2 local Proxy Address 10.60.0.0, remote Proxy Address 10.0.0.0, Crypto map (OUTSIDE-MAP)

Jun 18 2013 00:55:09: %ASA-5-713049: Group = 2.2.2.2, IP = 2.2.2.2, Security negotiation complete for LAN-to-LAN Group (2.2.2.2) Initiator, Inbound SPI = 0xd4218cd3, Outbound SPI = 0xf9a8108b

Jun 18 2013 00:55:09: %ASA-5-713120: Group = 2.2.2.2, IP = 2.2.2.2, PHASE 2 COMPLETED (msgid=c0a82858)

darenv · ‎06-21-2013

OK, having put this to TAC, I have been informed that this is the way it is. I intend to submit an enhancement request so that when DPD marks the peer as down that it flags it so for a period of time; either that or a user-definable timeout value for the beginning of the Phase 1 negotiation ...