L2TP / IPSec to Cisco router

Apr 21, 2005 2 Replies

Hi,



I successfully configured a Cisco router to accept VPN connections using L2TP over IPSec. Anyway, I have some behaviour that seems strange to me. I need to enable logging in the filtering rule that allows incoming ESP packets. Then everything works fine. If logging is disabled in this rule key exchange still works fine but the cisco does not respond to any ESP packets from the client anymore.



access-list 101 permit esp any host 9.9.9.9 NO RESPONSE FROM CISCO TO ESP PACKETS FROM CLIENT



access-list 101 permit esp any host 9.9.9.9 log WORKS FINE


Any ideas???


Can you share your configuration as it was asked time to time on this group?

Here's the Cisco config $(relevant parts):

!---------------------------------------------------------------------------- !version 12.2

hostname Cisco ! aaa new-model ! aaa authentication login default local aaa authentication ppp vpdn group radius aaa authorization network default group radius aaa session-id common ip subnet-zero no ip source-route ! vpdn enable ! vpdn-group l2tpvpn ! Default L2TP VPDN group accept-dialin protocol l2tp virtual-template 1 no l2tp tunnel authentication ! no ftp-server write-enable ! ! crypto ca trustpoint NetworklabDemoCA enrollment mode ra enrollment url http://172.16.4.1:80/certsrv/mscep/mscep.dll serial-number ip-address 192.168.0.2 revocation-check none ! ! crypto ca certificate chain NetworklabDemoCA certificate 61F92209000000000019 3082066B ........AE1F8E quit certificate ca 2927890E737263A64AF4E05E58515BF4 308204A2 ........4861 quit ! ! crypto isakmp policy 1 encr 3des group 2 ! ! crypto ipsec transform-set esp-3des-sha-tunnel esp-3des esp-sha-hmac ! crypto dynamic-map dynvpn 1 set transform-set esp-3des-sha-tunnel set pfs group2 match address 130 ! ! crypto map extmap 1 ipsec-isakmp dynamic dynvpn ! ! interface FastEthernet0 description $FW_OUTSIDE$$ETH-WAN$ ip address 9.9.9.9 255.255.255.0 ip access-group 101 in ip verify unicast reverse-path no ip redirects no ip unreachables no ip proxy-arp ip inspect DEFAULT100 out ip route-cache flow duplex auto speed auto no cdp enable crypto map extmap ! interface Virtual-Template1 ip unnumbered FastEthernet0 peer default ip address pool vpnpool ppp encrypt mppe 128 ppp authentication ms-chap-v2 vpdn ! interface Vlan1 description $FW_INSIDE$$ETH-SW-LAUNCH$$INTF-INFO-HWIC 4ESW$ ip address 192.168.0.2 255.255.255.0 ip access-group 100 in ip access-group sdm_vlan1_out out no ip redirects no ip unreachables no ip proxy-arp ip route-cache flow ip tcp adjust-mss 1452 ! ip local pool vpnpool 10.10.10.0 10.10.10.7 ip classless ip route 0.0.0.0 0.0.0.0 9.9.9.8 ip http server ip http authentication local ip http secure-server ! ! ! ip access-list extended sdm_vlan1_out remark SDM_ACL Category=1 remark RDP permit ip 10.10.10.0 0.0.0.7 host 192.168.0.1 permit tcp 10.10.10.0 0.0.0.7 host 192.168.0.1 eq 3389 deny ip any any logging trap debugging access-list 100 remark auto generated by SDM firewall configuration access-list 100 remark SDM_ACL Category=1 access-list 100 deny ip 9.9.9.0 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 tcp host 192.168.0.1 eq 3389 10.10.10.0 0.0.0.7 log access-list 100 permit ip any any log access-list 101 remark auto generated by SDM firewall configuration access-list 101 remark SDM_ACL Category=1 access-list 101 permit udp any eq isakmp host 9.9.9.9 eq isakmp access-list 101 permit esp any host 9.9.9.9 log access-list 101 deny ip 192.168.0.0 0.0.0.255 any access-list 101 permit icmp any host 9.9.9.9 echo-reply access-list 101 permit icmp any host 9.9.9.9 time-exceeded access-list 101 permit icmp any host 9.9.9.9 unreachable access-list 101 deny ip 10.0.0.0 0.255.255.255 any access-list 101 deny ip 172.16.0.0 0.15.255.255 any access-list 101 deny ip 192.168.0.0 0.0.255.255 any access-list 101 deny ip 127.0.0.0 0.255.255.255 any access-list 101 deny ip host 255.255.255.255 any access-list 101 deny ip host 0.0.0.0 any access-list 101 deny ip any any access-list 130 remark SDM_ACL Category=20 access-list 130 permit udp host 9.9.9.9 any eq 1701 access-list 130 permit udp any eq 1701 host 9.9.9.9 no cdp run ! radius-server host 192.168.0.1 auth-port 1645 acct-port 1646 key 7

13171634946917212E3D radius-server authorization permit missing Service-Type

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