11-04-2014 12:56 PM - edited 02-21-2020 07:54 PM
I am implementing GET VPN. I have set my KSs to receive-only mode, so all my GMs are in inbound-only mode. I did this because I want to see if there are problems with registration, I expect that if there are problems it will not affect production traffic.
However, I've encountered an issue where after a rekey, a router will stop forwarding traffic that matches the encryption policy with the error: %CRYPTO-4-RECVD_PKT_NOT_IPSEC
However, the routers are not doing encryption, and they should be accepting unencrypted data either way.
Here are some of the logs:
.Nov 4 08:41:21.053 AST: %GDOI-5-GM_RECV_REKEY: Received Rekey for group GDOI-GROUP1 from 10.0.0.2 to 192.168.248.68 with seq # 19
.Nov 4 08:41:21.169 AST: %GDOI-3-GDOI_REKEY_SEQ_FAILURE: Failed to process rekey seq # 19 in seq payload for group GDOI-GROUP1, last seq # 19
.Nov 4 08:41:21.169 AST: %GDOI-3-GDOI_REKEY_FAILURE: Processing of REKEY payloads failed on GM 192.168.248.68 in the group GDOI-GROUP1, with peer at 10.0.0.2
.Nov 4 08:41:21.169 AST: %CRYPTO-6-IKMP_MODE_FAILURE: Processing of GDOI mode failed with peer at 10.0.0.2
.Nov 4 08:41:31.289 AST: %GDOI-5-GM_RECV_REKEY: Received Rekey for group GDOI-GROUP1 from 10.0.0.2 to 192.168.252.102 with seq # 20
.Nov 4 08:41:41.349 AST: %GDOI-5-GM_RECV_REKEY: Received Rekey for group GDOI-GROUP1 from 10.0.0.2 to 192.168.249.4 with seq # 21
.Nov 4 10:28:56.135 AST: %GDOI-5-GM_RECV_REKEY: Received Rekey for group GDOI-GROUP1 from 10.0.0.2 to 192.168.248.68 with seq # 22
.Nov 4 10:28:56.259 AST: %GDOI-3-GDOI_REKEY_SEQ_FAILURE: Failed to process rekey seq # 22 in seq payload for group GDOI-GROUP1, last seq # 22
.Nov 4 10:28:56.259 AST: %GDOI-3-GDOI_REKEY_FAILURE: Processing of REKEY payloads failed on GM 192.168.248.68 in the group GDOI-GROUP1, with peer at 10.0.0.2
.Nov 4 10:28:56.259 AST: %CRYPTO-6-IKMP_MODE_FAILURE: Processing of GDOI mode failed with peer at 10.0.0.2
.Nov 4 10:29:06.367 AST: %GDOI-5-GM_RECV_REKEY: Received Rekey for group GDOI-GROUP1 from 10.0.0.2 to 192.168.252.102 with seq # 23
.Nov 4 10:29:16.443 AST: %GDOI-5-GM_RECV_REKEY: Received Rekey for group GDOI-GROUP1 from 10.0.0.2 to 192.168.249.4 with seq # 24
.Nov 4 12:16:31.209 AST: %GDOI-5-GM_RECV_REKEY: Received Rekey for group GDOI-GROUP1 from 10.0.0.2 to 192.168.248.68 with seq # 25
.Nov 4 12:16:31.357 AST: %GDOI-3-GDOI_REKEY_SEQ_FAILURE: Failed to process rekey seq # 25 in seq payload for group GDOI-GROUP1, last seq # 25
.Nov 4 12:16:31.361 AST: %GDOI-3-GDOI_REKEY_FAILURE: Processing of REKEY payloads failed on GM 192.168.248.68 in the group GDOI-GROUP1, with peer at 10.0.0.2
.Nov 4 12:16:31.361 AST: %CRYPTO-6-IKMP_MODE_FAILURE: Processing of GDOI mode failed with peer at 10.0.0.2
.Nov 4 12:16:41.437 AST: %GDOI-5-GM_RECV_REKEY: Received Rekey for group GDOI-GROUP1 from 10.0.0.2 to 192.168.252.102 with seq # 26
.Nov 4 12:28:56.546 AST: %CRYPTO-4-RECVD_PKT_NOT_IPSEC: Rec'd packet not an IPSEC packet. (ip) vrf/dest_addr= /192.168.18.50, src_addr= 10.128.3.13, prot= 6
.Nov 4 12:29:56.583 AST: %CRYPTO-4-RECVD_PKT_NOT_IPSEC: Rec'd packet not an IPSEC packet. (ip) vrf/dest_addr= /192.168.17.54, src_addr= 10.128.6.72, prot= 6
.Nov 4 12:30:56.647 AST: %CRYPTO-4-RECVD_PKT_NOT_IPSEC: Rec'd packet not an IPSEC packet. (ip) vrf/dest_addr= /192.168.6.71, src_addr= 10.128.6.72, prot= 6
.Nov 4 12:31:57.320 AST: %CRYPTO-4-RECVD_PKT_NOT_IPSEC: Rec'd packet not an IPSEC packet. (ip) vrf/dest_addr= /192.168.16.56, src_addr= 181.188.0.59, prot= 6
.Nov 4 12:32:57.525 AST: %CRYPTO-4-RECVD_PKT_NOT_IPSEC: Rec'd packet not an IPSEC packet. (ip) vrf/dest_addr= /192.168.17.48, src_addr= 10.128.6.72, prot= 6
.Nov 4 12:33:57.714 AST: %CRYPTO-4-RECVD_PKT_NOT_IPSEC: Rec'd packet not an IPSEC packet. (ip) vrf/dest_addr= /192.168.32.49, src_addr= 10.128.6.72, prot= 6
.Nov 4 12:34:57.758 AST: %CRYPTO-4-RECVD_PKT_NOT_IPSEC: Rec'd packet not an IPSEC packet. (ip) vrf/dest_addr= /192.168.17.46, src_addr= 10.128.3.20, prot= 6
Notice how the rekeys at 8 and 10 am happens (including the failure) and there is no issue, but somehow at 12 it poses a problem.
Here is the relevant config of my KS:
!
crypto isakmp policy 1
encr aes 256
authentication pre-share
group 2
crypto isakmp key ******** address 0.0.0.0 0.0.0.0
!
!
crypto ipsec transform-set gettransform esp-aes esp-sha-hmac
!
crypto ipsec profile MYPROFILE
set security-association lifetime seconds 7200
set transform-set gettransform
!
crypto gdoi group GDOI-GROUP1
identity number 100
server local
rekey algorithm aes 256
rekey retransmit 10 number 2
rekey authentication mypubkey rsa REKEYRSA
rekey transport unicast
sa receive-only
sa ipsec 1
profile MYPROFILE
match address ipv4 getvpn-acl
replay time window-size 5
address ipv4 10.0.0.2
redundancy
local priority 200
peer address ipv4 10.0.0.3
!
ip access-list extended getvpn-acl
deny udp any eq 848 any eq 848
deny esp any any
deny tcp any any eq 22
deny tcp any eq 22 any
deny udp any any eq 1645
deny udp any any eq 1646
deny udp any any eq 1812
deny udp any any eq 1813
deny tcp any eq 443 any
deny tcp any any eq 443
deny eigrp any any
deny udp any any eq ntp
deny udp any eq ntp any
deny udp any any eq snmp
deny udp any eq snmp any
deny udp any any eq snmptrap
deny udp any eq snmptrap any
deny udp any any eq syslog
deny udp any eq syslog any
permit ip any any
!
Here is the config of the GM:
!
crypto isakmp policy 1
encr aes 256
authentication pre-share
group 2
lifetime 300
crypto isakmp key ******** address 0.0.0.0 0.0.0.0
!
!
crypto gdoi group GDOI-GROUP1
identity number 100
server address ipv4 10.0.0.2
server address ipv4 10.0.0.3
!
!
crypto map gdoimap 1 gdoi
set group GDOI-GROUP1
!
!
interface FastEthernet0/1
description Connected to WAN 1
crypto map gdoimap
interface FastEthernet0/0/0
description Connected to WAN 2
crypto map gdoimap
!
I've looked to see if there are any bugs, but I can't find any.
The version of the KS and the GM is 12.4(24)T5.
*all IPs are sanitised for your protection
11-13-2014 02:41 AM
Hello Sganpat
As per my obervation , when we are using sa receive only then IPsec polices will applied for inbound traffic. So in your case when the traffic is comming from one , it comes out as plane text traffic because the group member installs this IPsec SA only in the inbound direction. So when this traffic reach at other end where the router is expecting the encrypted traffic in bound direction , Router drops the traffic and u start getting error msg.
Nov 4 12:28:56.546 AST: %CRYPTO-4-RECVD_PKT_NOT_IPSEC: Rec'd packet not an IPSEC packet. (ip) vrf/dest_addr= /192.168.18.50, src_addr= 10.128.3.13, prot= 6
Thanks
Vishaw
12-14-2015 02:11 AM
Sorry I took so long to answer this.
The SA Receive_Only allows traffic to be received either in encrypted or in plain text. It is used when rolling out GET VPN when all the routers have not been converted to group members. So you have misunderstood what the command does.
I ended up opening a case with Cisco TAC and they couldn't figure out what was happening.
What I eventually did was create a loopback address and have the GDOI configuration register with that address.
!
interface Loopback0
ip address 10.1.1.10 255.255.255.255
!
crypto map gdoimap local-address Loopback0
!
My theory is that because I had two WAN links, both were trying to register with the key server, but one was failing because the KS would see it as a duplicate registration. This may have been causing some problems with the GM.
Once I used that command, everything worked fine.
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