At router B, try this (instead of using the arp command) ifconfig eth1:10 10.10.10.10 netmask 255.255.255.0 up The idea is to create an alias interface (I'm using 10 but you can use any) at interface eth1 of router B. -- Jet (Security Analyst) http://www.secure-ip.com Steven Mugassa wrote: > Hello everyone, > > I have the following network setup: > > machine A<---->RouterA<---CIPE VPN--->RouterB<--->MachineB > > machineA & Router A are in LAN A and machine B & router B are in LAN B > > -Router A has interfaces eth0,eth1 and vpn interface 'cipcb0' > -Router B also has eth0,eth1, and cipcb0 > -Gateway of machine A is cipcb0 > -Gateway of machine B is not any interface in Router B > > machine A wants to access machine B, so i have decided to use > proxy-arp approach by reserving one IP address in range of LANB to > use for proxy-arp in the Router B. > The idea is that when a packet from A reaches Router B, it is SNATed > to that reserved IP address (call it 10.10.10.10) > So machine B will receive the packet as if it coming from > 10.10.10.10( in LAN B=10.10.10.0/24) > When machine B replies, its arp request broadcast will be answered by > Router B (with proxy-arp entry /sbin/arp -i eth1 -Ds 10.10.10.10 eth1 > pub). > > However, the situation is that when i do the tcpdump on Router B, i > observe the following > 12:02:56.227511 10.10.10.10 > 10.10.10.5: icmp: echo request (DF) > 12:02:56.227649 arp who-has 10.10.10.10 tell 10.10.10.5 > 12:02:57.226258 10.10.10.10 > 10.10.10.5: icmp: echo request (DF) > 12:02:57.226399 arp who-has 10.10.10.10 tell 10.10.10.5 > 12:02:58.227317 10.10.10.10 > 10.10.10.5: icmp: echo request (DF) > 12:02:58.227452 arp who-has 10.10.10.10 tell 10.10.10.5 > > where machine B = 10.10.10.5 > > According to this tcpdump i suspect that my proxy-arp configurations > are not working i.e. routerB doesn't accept arp request for > 10.10.10.10. > Where can be the problem then? What i know is that for proxy-arp i > only have to execute one line "/sbin/arp -i eth1 -Ds 10.10.10.10 eth1 > pub". Is there some more commands i should do? Or is the vpn > interface (cipcb0) causing the problems? > > Please advice, > > Thanks, > Steven
