Hello * community, I have 2 * boxes spanning a t1 with hdlc. I'm trying to route packets so people on a subnet seperate of the * boxes can browse the boxes on the * spanned subnet. The * boxes and the boxes on subnet controlled by * can see everything. The boxes on the seperate subnet inside the company can only see so far as the first * box and can't ping across the span. http://home.yottadot.org/christian/ I have two boxes on a span that are routing packets perfectly amongst themselves both ways and from internal to external just fine. What they're not doing in routing externally originating packets between themselves properly. Packets can get to the head box and I can hit both of it's interfaces, but I can't hit either of the interfaces on the second box. I can hit either interface on each box from either box. I can hit any external interface on the network and internet from either box. I can only hit both interfaces on the first box from the internal network and nothing on the second box or the boxes that the second box is the subnet gateway for. I have no way of testing if the lead box can ping a box on the .10 subnet which will be illustrated below, so I don't know if the packets are routing correctly there, but I doubt they are. Any hints would be appreciated: christian@yottadot.org routing table from first box: 192.168.1.0 192.168.253.254 255.255.255.0 UG 0 0 0 eth0 192.168.10.0 192.168.254.1 255.255.255.0 UG 0 0 0 hdlc0 localnet * 255.255.255.0 U 0 0 0 eth0 192.168.254.0 * 255.255.255.0 U 0 0 0 hdlc0 loopback * 255.0.0.0 U 0 0 0 lo default 192.168.253.254 0.0.0.0 UG 1 0 0 eth0 ------------------------------------------------------------- firewall from first box: #!/bin/bash IPTABLES=/usr/sbin/iptables #IPTABLES=echo EXTIF="eth0" INTIF="hdlc0" echo " External Interface: $EXTIF" echo " Internal Interface: $INTIF" echo " Clearing existing rules" $IPTABLES -P INPUT ACCEPT $IPTABLES -F INPUT $IPTABLES -P OUTPUT ACCEPT $IPTABLES -F OUTPUT $IPTABLES -P FORWARD ACCEPT $IPTABLES -F FORWARD $IPTABLES -F Allow $IPTABLES -X Allow $IPTABLES -t nat -F echo " Setting up packet routing" $IPTABLES -N Allow $IPTABLES -A Allow -m state --state ESTABLISHED,RELATED -i $INTIF -j ACCEPT $IPTABLES -A Allow -m state --state ESTABLISHED,RELATED -i $EXTIF -j ACCEPT $IPTABLES -A Allow -m state --state NEW -i $INTIF -j ACCEPT $IPTABLES -A Allow -m state --state NEW -i $EXTIF -j ACCEPT echo " Enabling SNAT (MASQUERADE) functionality on $EXTIF and $INTIF" $IPTABLES -t nat -A POSTROUTING -o $INTIF -j MASQUERADE $IPTABLES -t nat -A POSTROUTING -o $EXTIF -j MASQUERADE echo "1" > /proc/sys/net/ipv4/ip_forward ------------------------------------------------------------- routing table on second box: Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface localnet Avion_Asterisk_ 255.255.255.0 UG 0 0 0 eth0 localnet * 255.255.255.0 U 0 0 0 eth0 192.168.253.0 192.168.254.1 255.255.255.0 UG 0 0 0 hdlc0 192.168.254.0 192.168.254.1 255.255.255.0 UG 0 0 0 hdlc0 192.168.254.0 * 255.255.255.0 U 0 0 0 hdlc0 loopback * 255.0.0.0 U 0 0 0 lo default 192.168.254.1 0.0.0.0 UG 0 0 0 hdlc0 ------------------------------------------------------------- firewall on second box: #!/bin/bash IPTABLES=/usr/sbin/iptables #IPTABLES=echo EXTIF="hdlc0" INTIF="eth0" echo " External Interface: $EXTIF" echo " Internal Interface: $INTIF" echo " Clearing existing rules" $IPTABLES -P INPUT ACCEPT $IPTABLES -F INPUT $IPTABLES -P OUTPUT ACCEPT $IPTABLES -F OUTPUT $IPTABLES -P FORWARD ACCEPT $IPTABLES -F FORWARD $IPTABLES -F Allow $IPTABLES -X Allow $IPTABLES -t nat -F echo " Setting up packet routing" $IPTABLES -N Allow $IPTABLES -A Allow -m state --state ESTABLISHED,RELATED -i $INTIF -j ACCEPT $IPTABLES -A Allow -m state --state ESTABLISHED,RELATED -i $EXTIF -j ACCEPT $IPTABLES -A Allow -m state --state NEW -i $INTIF -j ACCEPT $IPTABLES -A Allow -m state --state NEW -i $EXTIF -j ACCEPT echo " Enabling SNAT (MASQUERADE) functionality on $EXTIF and $INTIF" $IPTABLES -t nat -A POSTROUTING -o $INTIF -j MASQUERADE $IPTABLES -t nat -A POSTROUTING -o $EXTIF -j MASQUERADE echo "1" > /proc/sys/net/ipv4/ip_forward ------------------------------------------- Here's the chart - I need to be able to ping boxes both ways across the span: router / gateway ( .1.254 ) | ---------- | | | |--- | -----------------External | | (.1.0 sub) | | (.253.254) | | (.253.253) -----same box --->(.254.1) | | --t1 span to another building---- | (.254.2)---same box---->---(.10.254) | | (.10.0 subnet) Thanks for even looking, Christian christian@yottadot.org