Stefann, You provide a very cool expample! Jim, You provide a great answer, especially in understanding of ISA's position (standing higher level based on RRAS and TCP/IP stack). Not sure those wording in English is correct or not, "ISA provides a logic but not physcial connection between two sites". > That is odd, but I'll bet you find that this behavior is the same > without ISA. > RRAS and the TCP/IP stack, not ISA, handle the actual packet routing. > > -------------------------------------------- > Jim Harrison > MCP(NT4, W2K), A+, Network+, PCG > http://isaserver.org/Jim_Harrison/ > http://isatools.org > Read the help / books / articles! > -------------------------------------------- > -----Original Message----- > From: Stefaan Pouseele [mailto:stefaan.pouseele@xxxxxxxxx] > Sent: Tuesday, December 27, 2005 4:58 AM > To: [ISAserver.org Discussion List] > Subject: [isalist] S2S VPN: why are static routes sometimes needed? > > http://www.ISAserver.org > > Hi, > > it seems that if a S2S VPN connection of type IPSec Tunnel is used and > if > the remote tunnel endpoint can't be reached through the default gateway, > then you need to create extra static routes for the remote network ID's > reachable through that remote tunnel endpoint. I don't understand why > this > is needed? Take note that there were no problems in setting up the IPSec > MM > and QM SA's! > > To explain it better, here is a little diagram of the lab setup: > > 192.168.1.0/24 > vvv > LAN-A -------- [ISA-A] ---+ > 192.168.22.0/24 .10 ! > +--- [RTR] --- Internet > ! .1 > .30 ! > [RTR-B] > ! .1 > .10 ! > LAN-B -------- [ISA-B] ---+ > 192.168.44.0/24 ^^^ > 192.168.11.0/24 > > > On ISA-A: > --------- > > Remote Site Network contains: > - 192.168.11.10/32 > - 192.168.44.0/24 > > Default gateway: 192.168.1.1 > > Static routes configured: > - 192.168.11.0/24 Gateway 192.168.1.30 > - 192.168.44.0/24 Gateway 192.168.1.30 <<<< WHY is this one needed ??? > > > On ISA-B: > --------- > > Remote Site Network contains: > - 192.168.1.10/32 > - 192.168.22.0/24 > > Default Gateway: 192.168.11.1 > > No static routes configured. > > > Test: > ----- > > From a host on LAN-B ping a host on LAN-A. Without the static route > '192.168.44.0/24 Gateway 192.168.1.30' on ISA-A, I can see the ping > request > and reply on LAN-A but the reply never makes it back to LAN-B. The ping > reply just disappeared into thin air! Creating the static route and > bingo, > it works. What's the logic behind this behavior? > > > Thanks, > Stefaan > > > ------------------------------------------------------ > List Archives: http://www.webelists.com/cgi/lyris.pl?enter=isalist > ISA Server Newsletter: http://www.isaserver.org/pages/newsletter.asp > ISA Server FAQ: http://www.isaserver.org/pages/larticle.asp?type=FAQ > ------------------------------------------------------ > Visit TechGenix.com for more information about our other sites: > http://www.techgenix.com > ------------------------------------------------------ > You are currently subscribed to this ISAserver.org Discussion List as: > jim@xxxxxxxxxxxx > To unsubscribe visit http://www.webelists.com/cgi/lyris.pl?enter=isalist > Report abuse to listadmin@xxxxxxxxxxxxx > > All mail to and from this domain is GFI-scanned.