luka73
Hello,
here's my first post on the site. I would very much like your feedback on the issue I have been having. here's a bit of background.
I have 3 sites connected via OpenVPN, with site2 and site3 connected to site1, via site-to-site ethernet bridging (tap interfaces).
I have installed OpenVPN on the Gateway/Firewall machine of each site.
site1 has multiples subnets and from within these subnets servers monitor and ping clients inside site2 and site3 subnets successfully. clients from site2 and site3 subnets can successfully ping servers within site1 subnets. It is all working fine and as I expected.
here's the problem I have been having. I wanted to implement MRTG on a server within a site1 subnet, to monitor the bandwidth of site1 (firewall/gateway/openvpn) router, and do the same for site2 and site3. the problem is this. from withing any subnet I can ping the gateway of any site and within any remote subnets, but when I try to ping from a gateway to gateway, via iptraf i can see that the ip addreess originating the ping request is tap0. if I type "ping x.x.x.x -I eth2" for instance because I wish the eth2 address to be originating the request and not tap0, ping fails. this is true for all of the sites.
so to recap, if I wish to ping from gateway to gateway, it pings fine because the source ip of the gateway is translated into tap0 address. however if I wish to ping with eth0 address of the gateway (see cmd above), the ping request fails and there is no trace of it anywhere (checked with iptraf on both gateways)
Firewalls log every single packet dropped, and logs show nothing at all, so I must be missing something.
I came across this problem when the MRTG server tried to sent SNMP requests to the site2 gateway from a server within site1 gateway. and although MRTG server can ping site2 gateway just fine, executing snmpwalk -v 1 -c public site2.eth2 fails because site2.eth2 (ping x.x.x.x -I eth2)cannot ping MRTG server or site1 for that matter.
Your help will be very much appreciated.
