[nzlug] ADSL modem for pppoe bridge (half bridge)

[Peter]

Ive since tried to repeat a half bridge setup using a different ISP in a different town with results which vary from those to date.

The hardware is the same: Billion 7100S modem + Debian Etch 
Whats different: Planet, instead of Xnet, ADSL off of a roadside cabinet instead of via copper to exchange.

What happens in this latest case is this:

MODEM Routing Table:
Destination 	Netmask 	Gateway 	Interface
0.0.0.0	0.0.0.0	202.27.217.4	ppp1
192.168.1.0	255.255.255.0	192.168.1.254	br0
127.0.0.1	255.0.0.0	127.0.0.1	lo0
202.27.217.4	255.255.255.255	202.27.211.182	ppp1 

Windows NIC status:     
Physical Address: 00-0E-A6-3E-1C-24
IP Address: 202.27.211.182
Subnet Mask: 255.255.255.0
Default Gateway: 202.27.211.183
DHCP Server: 192.168.1.254
Lease Obtained: 8/06/2008 7:23:45 a.m.
Lease Expires: 8/06/2008 7:24:45 a.m.
DNS Servers: 202.27.217.204, 202.14.102.1
WINS Server: 

Note the /24 netmask the modem has issued.

/sbin/route add -host 202.27.211.183 dev eth1 
/sbin/route add default gw 202.27.211.183 dev eth1 

gives me:
long pause then "host: Host name lookup failure"
and
SIOCADDRT: File exists 
respectively

after a reboot, and several route adds and deletes and route flushes, and another reboot

route does intitially come happyish, despite the errors above:

earthsong:/home/peter# route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
ip202-27-211-18 *               255.255.255.255 UH    0      0        0 eth1
202.27.211.0    *               255.255.255.0   U     0      0        0 eth1
localnet        *               255.255.255.0   U     0      0        0 eth0
default         ip202-27-211-18 0.0.0.0         UG    0      0        0 eth1

Planets gateway is within /16 of the IP its issued me, whereas Xnets was /0. In Xnets case the modem issued a /8 netmask, whereas with Planet a /24.

That would be all good and well except, that with Planet, rebooting  the server messes up route again, and it takes the same cajoling with mixed success to get the link up again playing around with route.

In the meantime ive set this particular box up with the modems DMZ function, and a 1:1 NAT mapping. It seems stable other than some network timeouts under heavy loads (which im fairly sure relate to having upgraded the firmware in the modem.)

Can anyone shed any more informed light on the static route hack?
And is there any news from Jack Pivac about the Draytec modem?
I could try the AM300, but not convinced that the half bridge hassles here are purely modem related. After all it works under windows, using Planet as it did on Xnet.

I have updated both WLUG entrys on this topic.

http://www.wlug.org.nz/Billion7100
http://www.wlug.org.nz/Half%20bridge%20with%20PPPoA

Regards

Peter Scott


-----------------------------
Xnet, billion, half bridge
----------------------------

Windows understanding:

Physical Address: 00-0E-A6-3E-1C-24
IP Address: 118.90.11.128
Subnet Mask: 255.0.0.0
Default Gateway: 118.90.11.129
DHCP Server: 192.168.1.254
Lease Obtained: 25/04/2008 1:25:48 p.m.
Lease Expires: 25/04/2008 1:26:48 p.m.
DNS Servers: 58.28.4.2, 58.28.6.2
WINS Server:

Debian seems to concur:

solarbus1:~# ifconfig eth1
eth1      Link encap:Ethernet  HWaddr 00:10:5A:80:87:D8
       inet addr:118.90.11.128  Bcast:255.255.255.255  Mask:255.0.0.0
       inet6 addr: fe80::210:5aff:fe80:87d8/64 Scope:Link
       UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
       RX packets:2186960 errors:0 dropped:0 overruns:0 frame:0
       TX packets:1749194 errors:0 dropped:0 overruns:0 carrier:0
       collisions:0 txqueuelen:1000
       RX bytes:980060481 (934.6 MiB)  TX bytes:381944794 (364.2 MiB)
       Interrupt:11 Base address:0xa000


The modems view a little different:

Destination      Netmask      Gateway      Interface
0.0.0.0        0.0.0.0        58.28.15.31    ppp1
192.168.1.0    255.255.255.0    192.168.1.254    br0
58.28.15.31    255.255.255.255    118.90.11.128    ppp1
127.0.0.1    255.0.0.0    127.0.0.1    lo0

Debian now says (without pause):

solarbus1:~# route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
localnet        *               255.255.255.0   U     0      0        0 eth0
118.0.0.0       *               255.0.0.0       U     0      0        0 eth1
default         ip-118-90-13-25 0.0.0.0         UG    0      0        0 eth1