Cisco VPN :: Configure IPsec L2L To Allow Only One Way Traffic
May 9, 2011
We have a business need that we have to set up a IPsec L2L tunnel (from multiple locations) to a business partner, we require that the connection can only be initiated from our side, not business partner side. I searched the web, one option is configure our side ASA to initate IKE only, this does not seem to meet our requirement, because once IPsec SA is up, IP layer traffic will flow freely in either direction; the other option people suggested is to use VPN filter in tunnel group policy, but the documention of how to use this vpn-filter to enforce one way traffic policy is not crystal clear to me; I actually configured reflexive ACL on core L3 switch before the traffic hits ASA to reflect/evalulate specific traffic to businness partner's LAN network, that worked well. However one of our branch office's core L3 switch is Cat4K which does not support reflexive ACL with the image it is currently running, so I am stuck again .
why my VPN setup is not working correctly. The device is an ASA 5505 running IOS version 8.2. It has a license for 2 SSL VPNS, and 25 IPSec VPNs. The previous Admin had set up both but only the SSL VPN apparently works. I attempted to set up my own IPSec VPN using the ASDM wizard, with an IP range of 192.168.40.10-50. I am connecting from a Mac, 10.6. My local network (home) is a standard 192.168.1.0/24; the remote networks are 192.168.2.0 and 192.168.3.0. I tried connecting using the built-in Snow Leopard client, and although it said I was connected I couldn't actually contact anything on the corporate LAN.\
I have configured the IPsec vpn between Cisco 877 and ISA server which is working fine and ok. But the issue is I have multiple subnet on the TMG "Treat Managmenet Gateway" side and only one subnet on the Cisco 877 side. I can only sending some subnet's traffics from Cisco 877 through the vpn tunnel to the other side which is TMG server and I have recieved teh timeout request for the rest of teh subnets.
However, if I initiated the ping from inside the ISA with different sources , I can reached the Cisco 877 and from then I can be able to send traffic.
So, the tunnel is up and active but it should be initated from ISA server to have a full connectivity.
I have C1841 as EZVPN server and remote C1841 as EZVPN client. Connection between them is providers L3 VPN, so it is not over the internet. IPSec tunnels go up with no problem. Client is NEM. Problem is that traffic won't go via IPSec. No packets are encapsulated. I want all trafiic to go via tunnel, no split tunneling here. On client side Dialer0 is outside interface, since L3 VPN is over ADSL. On server's side I have only one interface connected to corporate network. Peer address is server's loopback address.
After IPSec is up, server gets remote subnets as static routes and redistribute them to OSPF. That part works fine, but remote site's traffic doesn't flow over IPSec to the coorporate LAN. Could be TCP MSS or something like that?
I am trying to pass Traffic thru the IPSEC tunnel but it does not work ([Cisco Router 892] <---> [Cisco ASA 5510] <---> [Cisco Router 892]) The Cisco ASA 5510 doesn't pass traffic UDP=500 & UDP=4500 ports...
I have a Site to Site IPSEC VPN Tunnel created with ASDM wizard.
Cisco ASA-5505 Peer A: x.x.x.x Lan A: 192.168.0.0 255.255.255.0 Fortinet FortiGate-50b Peer B: y.y.y.y Lan B: 192.168.23.0 255.255.255.0
I start traffic from LAN B with a ping (or telnet it doesn't matter) that receive no reply but tunnel goes up fine.
"show isakmp sa" seems ok (says "State : MM_ACTIVE") "show ipsec sa" seems ok but all #pkts are zero
try ftp, telnet from LAN B to LAN A systems but no one work. "show ipsec sa" all #pkts are zero As soon as I generate traffic from LAN A to LAN B these works (with tunnel already up) also traffic from LAN B to LAN A works.Obviously if I end VPN and start tunnel making traffic from LAN A all work fine bidirectionally, LAN A reach LAN B and LAN B reach LAN A.No msg logged in either two appliance.
Seems a very strange problem because seems not related to Phase1 or Phase2 already established.Traffic (routing ?) start works only after at least one packet goes from LAN A to LAN B.No msg logged in either two appliance.Problems begun in ASA version 8.0(4) ASDM version 6.1(3) and remain/continue after upgrade to ASA Version 8.4(1) ASDM version 6.4(1).
We are currently experiencing a problem on an IP SEC VPN tunnel that has all of us here completely stumped. We are hoping that one of you experts out there will be able to assist. Here are some basic details:
NETWORKS An IPSEC site to site tunnel has been built between the two sites on different networks. PIX 515E - MAIN SITE Network 172.16.0.0/24 CISCO 1841 - REMOTE SITE Network 172.16.99.0/24
ISSUE All traffic flows over the VPN from the 172.16.99.0 network in the direction of the Pix, such as RDP, SIP etc. Pings will go in both directions across the tunnel. Other than the pings most traffic will NOT flow over the tunnel from the 172.16.0.0 network on the pix to the 172.16.99.0 network on the 1841. It would appear that something on the 1841 is blocking traffic coming in over the tunnel from the 172.16.0.0 network as we can not get a wire shark capture on a PC on the 172.16.99.0 network, other than the ICMP traces. Usually this is an access list problem but we have checked and double checked the configuration and can't see anything.
TROUBLESHOOTING SO FAR
1. Have tried inserting various access list changes to the tunnel on the 1841 to make specific reference to the 172.16.0.0 network. 2. Have tried various NAT entries. 3. Have removed and then recreated the VPN tunnel from a fresh start. 4. Have made the MTU 1400 on the inside interfaces on the Pix and the 1841.
The tunnel is fully up at all times and as we say can ping in both directions.
All of my remote sites use various routers to route all of their traffic via IPsec. However, I have one WRVS4400N w/firmware 188.8.131.52 configured with a working tunnel. My issue is I need to set the Remote Group to 0.0.0.0 0.0.0.0 so all traffic is forced via IPsec tunnel and not out the local gateway. When I do the error, Remote Security Group and Local Security Group cannot be in the same network. However, it works with Cisco/Linksys RV042.
We have multiple vpn tunnels coming to our cisco asa 5520 , the problem is that when we create another tunnel with the same network as another network on the firewall , it does not know how to route the traffic to which interface or sub interface.
I am trying to set up a LAN-to-LAN VPN tunnel between two sites. One site has a 5505, and the other site has a 5510. It looks like the tunnel is being established fine (both ISAKMP and IPSEC SAs look OK), but traffic doesn't appear to be routing across the internet between the devices. [code]
We have many VPN tunnels back to our corporate office. All of these tunnels are very slow (same with our client VPN's). Our main firewall device at the corporate office is an ASA5510. We have a 100 Mb/sec Metro Ethernet internet connection here. We do not allow split-tunneling.
Our remote sites vary. We have DSL connections, cable internet connections, and other types of broadband that vary in speeds from 5 to 100 Mb/sec (up and down). The remote sites mostly have PIX 501's, but we have an ASA 5505 in one of the locations.
To take an example. On one of our remote sites that has a 100 Mb/sec connection, if I ping device to device, I'm getting ping times of about 50ms. And I'm pinging back through another 100 Mb/sec connection. If I get on a computer down there and run a speed test, I'm showing down speeds of about 1.5 Mb/sec... nowhere near 100. Some of that could be due to the lack of split tunneling, but I also suspect this could be an MTU issue.
Right now, all my MTU's are just set to the default 1500. Perhaps this is too high. I used this site to check my max: [URL]
I did a few tests from behind several of my firewalls. I pinged from a machine on one side of the tunnel to the firewall on the other end. I'm assuming the max MTU I come up with is the max MTU for the firewall I'm behind while pinging, right? The max amounts I came up with for some of my devices were as follows: Corporate ASA 5510 > 1272 (if you add the 28 byte packet header that would make it 1300) Remote PIX 501 > 1416 (if you add the 28 byte packet header that would make it 1444) Remote ASA 5505 > 1418 (if you add the 28 byte packet header that would make it 1446)
So, do I just need to set my MTU values to the appropriate amounts? I have tried changing the value, but I don't see any change in speed/performance. But I also don't know if I need to reboot the firewalls after changing the MTU. I know with Catalyst switches, you have to reload. But I didn't see any messages about needing to reboot on the ASA's/PIX's.
I currently have my 5505 setup for AnyConnect SSL VPN connections. Is it possible to also configure the 5505 for IPSec VPN connections? So, essentially my ASA will be capable of running SSL and IPSec VPN tunnels, concurrently.
we are going to build L2L IPSEC VPN on ASR 1004 at our new datacenter edge. but i don't find any familiar CLI on my 1004. any special license,IOS-XE version or processor is required ? ASR1000-ESP10 is necessary ?
I'm attempting to configure a tunnel on a PIX-501 version 6.3. It's an old device that's due to be replaced soon, but unfortunately we need a tunnel now... I have been using this document as a reference (6211): URL ,The remote end is a sonicwall.
The problem seems to be that the pix never sees the interesting traffic for the tunnel, and never tries to initiate a connection. I have enabled crypto ipsec and crypto isakmp debugs, but no data is ever displayed, even when attempting to access a device on the remote side of the tunnel! Someone had tried to set up this device with some tunnels in the past, but was never successful, so I'm thinking there might be remaining commands in the running-config causing problems.
we have two 2851's. One in Australia, one in NZ, IPsec VPN between the two.
We have multiple subnets behind the tunnels. From all the sunbets in Aus we can reach all the subnets in NZ, except for one. From NZ we can reach all the subnets in Aus. The traceroute and pings from the subnet in question in Aus goes out the internet interface of the router instead of going into the tunnel.
The subnets in question are 10.110.220/24 (Aus), 10.110.250/24 (NZ)
The access lists at both ends cover the traffic required but for some reason when leaving Australia the traffic is not captured by:
I've replaced real networkID to the one mentined below.
Topology: classical IPSec VPN tunnel between two Cisco 892s, with pre-shared key and no GRE. One 892 (branch_892) has access to the Internet via PPPoE and has three networks/vlans behind it. One VLAN is NATed to access internet via the PPPoE. Access to two other VLANs - VL92 (100.100.200.0/24) and VL93 (100.100.100.0/24) need is done thrue the VPN tunnel.
Second 892 (892_DC) has just one interface - WAN on Gigabit enabled/connected and has a static route to the default GW. It does not have any interal network defined. So the router is strictly used to send traffic for VL92/VL93 to the branch 892 via IPSec tunnel.
Here is the problem: access to/from VL93 (100.100.100.0/24) works, however for VL92 (100.100.100.0/24) - does not.
From devices in VL92 I can ping the 892_DC IP address across the VPN tunnel. From the 892_DC router I can also ping devices in VL92. However I can no ping from VL92 any device beyond the 892_DC and at the same time packet arriving on 892_DC for VL92 are not sent out via the VPN tunnel.
I took the packet trace on 892_DC using capture point/buffer to capute packets for VL92 and could see that traffic does arrive at the 892_DC. I run the same capute on Branch_892 and there was not a single packet.More interesting I modified the access list such a way that left on VL92 and still - no packets are sent out thru the tunnel. [code]
I have an issue where I can get traffic to pass from HDQ to two branch offices over our ipsec/gre tunnels even though the tunnels appear to be UP. The HDQ is a 2811, branch is a home office using an 871W and branch runs a 2801 router. I initially had HDQ working fine with the 871W but when I configured branch2 (2801), they both broke. The tunnels appear to be up but traffic is not routing across them. The two 2801 routers run 12.4 (c2800nm-adventerprisek9-mz.124-24.T2.bin). These are gre over ipsec tunnels. Currently traffic flows over an exsting MPLS network that we are getting away from due to cost. As soon as I change the routes to point to the Tunnels, it breaks. Traffic doesn't appear to pass through the tunnel. I have attached my sanitized configs.
HDQ#sh crypto sessCrypto session current status Interface: FastEthernet0/1Session status: UP-ACTIVEPeer: 184.108.40.206 port 500 IKE SA: local 220.127.116.11/500 remote 18.104.22.168/500 Active IPSEC FLOW: permit 47 0.0.0.0/0.0.0.0 0.0.0.0/0.0.0.0 Active SAs: 4, origin: crypto map IPSEC FLOW:
I am trying to configure an IPSEC vpn on an ASA5505 I setup an SSL vpn and it works fine, I can browse to the https: address log in and connnect to servers However when I try to setup the ipsec client access vpn it will not connect and I am getting the errors below I used the wizard for the initial configuration Looks like the inital IKE is being blocked or dropped?
%ASA-7-710005: UDP request discarded from my external IP/35781 to external:ASA-external/500 %ASA-7-710005: UDP request discarded from my external IP/35781 to external:ASA-external/137
We have purchased a couple of Cisco 891 routers - both are running IOS 15.0(1) M5 licensed with advanced IP services (default). The literature for these devices on Cisco's website claims they support IPsec stateful failover on advanced IP services.
Our intention is to configure them with HSRP and IPsec stateful failover to provide a highly-available default gateway and VPN end-point.
I have configured HSRP and that seems to work fine. My problem is that I cannot configure IPsec stateful failover. The documentation that I have found implies that I need to configure inter-device redundancy on a particular HSRP group and use the physical IP addresses on the interfaces within that group to allow stateful failover communication between the routers however the routers do not recognise the 'redundancy' command in config mode...
We have problems on central firewall with restricting traffic coming from remote office from IPsec. (The network sheme is attached) All branch offices are connected to central asa though IPsec. The main aim is to rule access from branch offices only on the central firewall, NOT on each IPsec tunnel According to the sheme:172.16.1.0/24 is on of the branch office LANs10.1.1.0/24 and 10.2.2.0/24 are central office LANThe crypto ACL looks like permit ip 172.16.1.0/24 10.0.0.0/8 the aim is to restrict access from 172.16.1.0/24 to 10.1.1.0/24 When packets are generated from host 10.1.1.10 to 172.16.1.0/24 all is ok - they are dropped by acl2 When packets are generated from 172.16.1.0/24 to 10.1.1.10 they are not dropped by any ACL - the reason is stateful firewall - traffic bypasses all access lists on a back path I thought that TCP State Bypass feature can solve this problem and disable stateful firewall inspection for traffic coming from 172.16.1.0/24 to 10.1.1.0/24, but it didn't work.The central asa 5500 is configured according to cisco doc [URL]