How to configure an ethernet dev as PtP ?
Hello all,
I tried to configure an ethernet device as a pointopoint link recently, just to find out that this does not work as one would expect via:
ifconfig eth0 192.168.1.1 pointopoint 192.168.5.1 up
I tried on kernel 2.4.21-pre6 and 2.2.19 (just to name two), both the same. It comes up as:
eth0 Link encap:Ethernet HWaddr 00:04:76:F7:E9:17
inet addr:192.168.1.1 Bcast:192.168.1.255 Mask:255.255.255.0 UP BROADCAST MULTICAST MTU:1500 Metric:1
I do not understand why this does not work out just like another ptp-interface like isdn:
isdn0 Link encap:Ethernet HWaddr FC:FC:00:00:00:00
inet addr:192.168.1.1 P-t-P:192.168.5.1 Mask:255.255.255.255 UP POINTOPOINT RUNNING NOARP MTU:1500 Metric:1
Is there anything I mis-understood or a good reason for not being able to make eth pointopoint?
I have the feeling this question is pretty brain-dead, but anyway, maybe some kind soul can drop a few words ...
Signature · 2 lines
Regards, Stephan
Quoted 21 lines · Stephan von Krawczynski
Hello all,
I tried to configure an ethernet device as a pointopoint link recently, just to find out that this does not work as one would expect via:
ifconfig eth0 192.168.1.1 pointopoint 192.168.5.1 up
I tried on kernel 2.4.21-pre6 and 2.2.19 (just to name two), both the same. It comes up as:
eth0 Link encap:Ethernet HWaddr 00:04:76:F7:E9:17
inet addr:192.168.1.1 Bcast:192.168.1.255 Mask:255.255.255.0 UP BROADCAST MULTICAST MTU:1500 Metric:1I do not understand why this does not work out just like another ptp-interface like isdn:
isdn0 Link encap:Ethernet HWaddr FC:FC:00:00:00:00
inet addr:192.168.1.1 P-t-P:192.168.5.1 Mask:255.255.255.255 UP POINTOPOINT RUNNING NOARP MTU:1500 Metric:1
Quoted 8 lines
Is there anything I mis-understood or a good reason for not being able to make eth pointopoint?
I have the feeling this question is pretty brain-dead, but anyway, maybe some kind soul can drop a few words ...
--
Regards,
Stephan
Because ethernet is not a point-to-point interface. At the hardware level, ethernet talks from one hardware address to another hardware address, i.e., the IEEE station address. You need ARP to find out what that address is so you can't "get there from here." But, you can do essentially the same thing, you set up a host route on that interface.
Use a 'private' network address...
On one host:
ifconfig eth1 10.0.0.1 netmask 255.255.255.0 broadcast 10.0.0.255 route add -host my-router-ip-address dev eth1
On the other host:
ifconfig eth1 10.0.0.2 netmask 255.255.255.0 broadcast 10.0.0.255 route add -host my-client-ip-address dev eth1
Cheers,
Dick Johnson
Penguin : Linux version 2.4.20 on an i686 machine (797.90 BogoMips). Why is the government concerned about the lunatic fringe? Think about it.
Quoted 32 lines · On Tue, 15 Apr 2003 08:10:59 -0400 (EDT) "Richard B. Johnson"…
Quoted 21 lines · Stephan von Krawczynski
Hello all,
I tried to configure an ethernet device as a pointopoint link recently, just to find out that this does not work as one would expect via:
ifconfig eth0 192.168.1.1 pointopoint 192.168.5.1 up
I tried on kernel 2.4.21-pre6 and 2.2.19 (just to name two), both the same. It comes up as:
eth0 Link encap:Ethernet HWaddr 00:04:76:F7:E9:17
inet addr:192.168.1.1 Bcast:192.168.1.255 Mask:255.255.255.0 UP BROADCAST MULTICAST MTU:1500 Metric:1I do not understand why this does not work out just like another ptp-interface like isdn:
isdn0 Link encap:Ethernet HWaddr FC:FC:00:00:00:00
inet addr:192.168.1.1 P-t-P:192.168.5.1 Mask:255.255.255.255 UP POINTOPOINT RUNNING NOARP MTU:1500 Metric:1Quoted 8 lines
Is there anything I mis-understood or a good reason for not being able to make eth pointopoint?
I have the feeling this question is pretty brain-dead, but anyway, maybe some kind soul can drop a few words ...
--
Regards,
Stephan
Quoted 6 lines
Because ethernet is not a point-to-point interface. At the hardware level, ethernet talks from one hardware address to another hardware address, i.e., the IEEE station address. You need ARP to find out what that address is so you can't "get there from here." But, you can do essentially the same thing, you set up a host route on that interface.
Well, the world today really knows ptp-type ethernet-interfaces in WAN environment, this is where the question comes from. Think of simply a two-ended bridged WAN connection. It is in fact (like) ptp.
Quoted 1 line
Use a 'private' network address...
That is only a _good_ alternative on first sight, but thinking again about it you might as well say that in a rather big-sized WAN environment with lots of hosts involved that route all kinds of private ips it is a really nice idea to connect the interconnecting wan-boxes with ptp _not_ burning down additional (private) subnets without real need. (remember, if you have lots of wan connections you need lots of private subnets, but if you could use ptp you need _none_)
Signature · 2 lines
Regards, Stephan
Quoted 6 lines · Stephan von Krawczynski
Hello all,
I tried to configure an ethernet device as a pointopoint link recently, just to find out that this does not work as one would expect via:
ifconfig eth0 192.168.1.1 pointopoint 192.168.5.1 up
How about:
/sbin/ip ad ad 192.168.1.1 peer 192.168.5.1 dev eth0
this gives:
# /sbin/ip ad
1: lo: <LOOPBACK,UP> mtu 16436 qdisc noqueue
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 brd 127.255.255.255 scope host lo
2: eth0: <BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast qlen 100
link/ether 00:06:5b:a2:b3:8a brd ff:ff:ff:ff:ff:ff
inet 192.168.1.1 peer 192.168.5.1/32 scope global eth0Does that do what you want?
Chris
Signature · 4 lines
Chris Friesen | MailStop: 043/33/F10 Nortel Networks | work: (613) 765-0557 3500 Carling Avenue | fax: (613) 765-2986 Nepean, ON K2H 8E9 Canada | email: [email protected]