Stephen- Stephen Hemminger wrote: > > The bridging code only works for devices that have Ethernet headers. > That is the way the bridging 802.2 standard works, it is a Layer 2 bridge > and it uses the address information from Ethernet to do routing. > > PPP does not use Ethernet level framing so it can't be bridged. > What were you trying to do? there are plenty of other ways to get the > same effect. Makes sense, I suppose (The forwarding is complicated by a p-p link without a destination mac addr that looks like ethernet). I expected that someone had built a table to do the mappings because the docs I referenced in the original post specifically say that ppp can be bridged. What I'm trying to do is a simple/low latency forward from a vpn concentrator/firewall/router out to a cellular WAN modem that attaches to a USB. My firewall lacks the USB interface so I simply need to forward packets between the USB and ethernet. Am doing it now at layer 3 (using iptables to do NAT) but that adds a lot of complexity and my firewall already does NAT (so it's happening twice). I haven't yet tested an ipsec tunnel over the link, but am concerned that I may also need to add ipsec passthrough if I do this at layer 3. All in all, a simple layer 2 forward between eth0 and ttyUSB0 is what I really need. /Lou _______________________________________________ Bridge mailing list Bridge@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/bridge
