Site to Site VPN monitor status is "up" on active and "down" on passive firewall

Site to Site VPN monitor status is "up" on active and "down" on passive firewall

2809
Created On 04/06/22 02:55 AM - Last Modified 10/23/24 21:33 PM


Symptom


  • Site to Site VPN monitor status is "up" on active firewall however showing "down" on passive firewall.
  • For example, in this output, we can see tunnel id 7 and 8 is "down" on passive firewall
  • VPN flow output on Active Firewall: 
> show vpn flow
total tunnels configured:                                     8
filter - type IPSec, state any

total IPSec tunnel configured:                                8
total IPSec tunnel shown:                                     8

id    name                          state   monitor local-ip                      peer-ip                       tunnel-i/f  
--    ----                          -----   ------- --------                      -------                       ----------  
1     VPN-FWSING01                  active  up      10.16.192.126                 10.18.199.14                  tunnel.1    
2     VPN-FWSING02                  active  up      10.16.192.126                 10.18.199.22                  tunnel.2    
5     VPN-FWCEFI                    active  up      10.16.192.110                 10.50.182.206                 tunnel.3    
4     VPN-FWGERL                    active  up      10.16.192.110                 10.24.133.4                   tunnel.4    
6     VPN-FWBORD                    active  up      10.16.192.110                 10.24.136.4                   tunnel.5    
7     VPN-FWBAST                    active  up      10.16.192.110                 10.24.16.4                    tunnel.6    
8     VPN-FWAJAC                    active  up      10.16.192.110                 10.24.2.4                     tunnel.7    
9     VPN-FWPLCF                    init    down    10.16.192.110                 10.50.198.204                 tunnel.8
  • VPN flow output on Passive Firewall: 
> show vpn flow
total tunnels configured:                                     8
filter - type IPSec, state any

total IPSec tunnel configured:                                8
total IPSec tunnel shown:                                     8

id    name                          state   monitor local-ip                      peer-ip                       tunnel-i/f  
--    ----                          -----   ------- --------                      -------                       ----------  
1     VPN-FWSING01                  active  up      10.16.192.126                 10.18.199.14                  tunnel.1    
2     VPN-FWSING02                  active  up      10.16.192.126                 10.18.199.22                  tunnel.2    
5     VPN-FWCEFI                    active  up      10.16.192.110                 10.50.182.206                 tunnel.3    
4     VPN-FWGERL                    active  up      10.16.192.110                 10.24.133.4                   tunnel.4    
6     VPN-FWBORD                    active  up      10.16.192.110                 10.24.136.4                   tunnel.5    
7     VPN-FWBAST                    active  down      10.16.192.110                 10.24.16.4                    tunnel.6    
8     VPN-FWAJAC                    active  down      10.16.192.110                 10.24.2.4                     tunnel.7    
9     VPN-FWPLCF                    init    down    10.16.192.110                 10.50.198.204                 tunnel.8


 



Environment


  • Palo Alto Firewalls
  • Supported PAN-OS
  • IPSEC VPN


Cause


  • VPN tunnel monitor did not refresh on passive firewall and stuck up with last status "down".
  • SPI mismatch is shown below between the active and passive firewall.
  • IPSec SA state on Active Firewall:
>show vpn ipsec-sa
GwID/client IP  TnID   Peer-Address           Tunnel(Gateway)                                Algorithm          SPI(in)  SPI(out) life(Sec/KB)             remain-time(Sec)        
--------------  ----   ------------           ---------------                                ---------          -------  -------- ------------             ----------------        
1               1      10.18.199.14           VPN-FWSING01(FWSING01)                         ESP/A256/SHA256    D956EA0F F954FBDB 3600/Unlimited           3454                     
2               2      10.18.199.22           VPN-FWSING02(FWSING02)                         ESP/A256/SHA256    E75AB051 C75863BB 3600/Unlimited           3429                     
4               4      10.24.133.4            VPN-FWGERL(FWGERL00A11401-FWGERL0A0E0701)      ESP/A256/SHA256    A4289A3C 9C4D6B34 3600/Unlimited           3513                     
3               5      10.50.182.206          VPN-FWCEFI(FWCEFI00AP3201-FWCEFI00AP1001)      ESP/A256/SHA256    EDFA3DB9 ACB90772 3600/Unlimited           3006                     
5               6      10.24.136.4            VPN-FWBORD(FWBORD0A1S6101-FWBORD0A1S0401)      ESP/A256/SHA256    A98B6650 EE1CCC94 3600/Unlimited           3470                     
6               7      10.24.16.4             VPN-FWBAST(FWBAST00A01601-FWBAST0A1S2601)      ESP/A256/SHA256    A9FA47D6 ECC0306F 3600/Unlimited           3171                     
7               8      10.24.2.4              VPN-FWAJAC(FWAJAC0A1S1201-FWAJAC0A1S1101)      ESP/A256/SHA256    96BDC835 DB437AAC 3600/Unlimited           1044        
  • IPSec SA state on Passive Firewall:
>show vpn ipsec-sa
GwID/client IP  TnID   Peer-Address           Tunnel(Gateway)                                Algorithm          SPI(in)  SPI(out) life(Sec/KB)             remain-time(Sec)        
--------------  ----   ------------           ---------------                                ---------          -------  -------- ------------             ----------------        
1               1      10.18.199.14           VPN-FWSING01(FWSING01)                         ESP/A256/SHA256    D956EA0F F954FBDB 3600/Unlimited           2185                     
2               2      10.18.199.22           VPN-FWSING02(FWSING02)                         ESP/A256/SHA256    E75AB051 C75863BB 3600/Unlimited           2160                     
4               4      10.24.133.4            VPN-FWGERL(FWGERL00A11401-FWGERL0A0E0701)      ESP/A256/SHA256    A4289A3C 9C4D6B34 3600/Unlimited           2244                     
3               5      10.50.182.206          VPN-FWCEFI(FWCEFI00AP3201-FWCEFI00AP1001)      ESP/A256/SHA256    EDFA3DB9 ACB90772 3600/Unlimited           1737                     
5               6      10.24.136.4            VPN-FWBORD(FWBORD0A1S6101-FWBORD0A1S0401)      ESP/A256/SHA256    A98B6650 EE1CCC94 3600/Unlimited           2201                     
6               7      10.24.16.4             VPN-FWBAST(FWBAST00A01601-FWBAST0A1S2601)      ESP/A256/SHA256    A9FA47D6 ECC0306F 3600/Unlimited           1902                     
7               8      10.24.2.4              VPN-FWAJAC(FWAJAC0A1S1201-FWAJAC0A1S1101)      ESP/A256/SHA256    EADEC3AA 89679FFD 3600/Unlimited           2815       



 



Resolution


  1. Manually sync the runtime session state between the firewalls using the following CLI command on the active Firewall.
  • >request high-availability sync-to-remote runtime-stat
  1. VPN monitor status will sync and it will be "up" on secondary firewall.
> show vpn flow
total tunnels configured:                                     8
filter - type IPSec, state any

total IPSec tunnel configured:                                8
total IPSec tunnel shown:                                     8

id    name                          state   monitor local-ip                      peer-ip                       tunnel-i/f  
--    ----                          -----   ------- --------                      -------                       ----------  
1     VPN-FWSING01                  active  up      10.16.192.126                 10.18.199.14                  tunnel.1    
2     VPN-FWSING02                  active  up      10.16.192.126                 10.18.199.22                  tunnel.2    
5     VPN-FWCEFI                    active  up      10.16.192.110                 10.50.182.206                 tunnel.3    
4     VPN-FWGERL                    active  up      10.16.192.110                 10.24.133.4                   tunnel.4    
6     VPN-FWBORD                    active  up      10.16.192.110                 10.24.136.4                   tunnel.5    
7     VPN-FWBAST                    active  up      10.16.192.110                 10.24.16.4                    tunnel.6    
8     VPN-FWAJAC                    active  up      10.16.192.110                 10.24.2.4                     tunnel.7    
9     VPN-FWPLCF                    init    down    10.16.192.110                 10.50.198.204                 tunnel.8


 



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