| Xen3 question |
[Jun. 3rd, 2006|12:50 pm]
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I know Xen2. New to Xen3.....
Loving all the improvements (one U/0 kernel, improved balloon, primary eth not in bridget, ...) but trying to understand that last one.
What is this peth0 device that's in the xenbr0 bridge now?sammy:/etc/xen# brctl show
bridge name bridge id STP enabled interfaces
xenbr0 8000.feffffffffff no vif5.0
peth0
vif0.0
sammy:/etc/xen# ifconfig
eth0 Link encap:Ethernet HWaddr 00:0C:F1:79:11:8D
inet addr:10.0.0.81 Bcast:10.0.0.255 Mask:255.255.255.0
inet6 addr: fe80::20c:f1ff:fe79:118d/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:45185 errors:0 dropped:0 overruns:0 frame:0
TX packets:30229 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:53881559 (51.3 MiB) TX bytes:2913325 (2.7 MiB)
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:489 errors:0 dropped:0 overruns:0 frame:0
TX packets:489 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:47785 (46.6 KiB) TX bytes:47785 (46.6 KiB)
peth0 Link encap:Ethernet HWaddr FE:FF:FF:FF:FF:FF
inet6 addr: fe80::fcff:ffff:feff:ffff/64 Scope:Link
UP BROADCAST RUNNING NOARP MULTICAST MTU:1500 Metric:1
RX packets:45460 errors:0 dropped:0 overruns:0 frame:0
TX packets:30491 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:54092321 (51.5 MiB) TX bytes:3142684 (2.9 MiB)
Base address:0xac00 Memory:ff4e0000-ff500000
vif0.0 Link encap:Ethernet HWaddr FE:FF:FF:FF:FF:FF
inet6 addr: fe80::fcff:ffff:feff:ffff/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:30252 errors:0 dropped:0 overruns:0 frame:0
TX packets:45231 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:2915659 (2.7 MiB) TX bytes:53885585 (51.3 MiB)
vif5.0 Link encap:Ethernet HWaddr FE:FF:FF:FF:FF:FF
inet6 addr: fe80::fcff:ffff:feff:ffff/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:161 errors:0 dropped:0 overruns:0 frame:0
TX packets:357 errors:0 dropped:347 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:93615 (91.4 KiB) TX bytes:36520 (35.6 KiB)
xenbr0 Link encap:Ethernet HWaddr FE:FF:FF:FF:FF:FF
inet6 addr: fe80::200:ff:fe00:0/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:1642 errors:0 dropped:0 overruns:0 frame:0
TX packets:6 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:144659 (141.2 KiB) TX bytes:468 (468.0 b)
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| Comments: |
![[User Picture]](http://l-userpic.livejournal.com/51462672/477231) | From:  skx
2006-06-03 08:06 pm (UTC)
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I'm suprised this isan't a FAQ actually...
By default Xen creates the xenbr0 bridge, moves eth0 there (renamed to peth0) and connects a virtual eth0 in dom0. So peth0 is the "renamed" eth0.
![[User Picture]](http://l-userpic.livejournal.com/53176443/1151536) | From: askbjoernhansen
2006-06-03 08:44 pm (UTC)
Doesn't work with more than one interface ... | (Link)
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If you have more than one interface and/or aliases it might not work. At least on fedora it doesn't.
Am I to infer that this a result of a certain design decision of Linux bridging where the bridge intercepts all traffic from the member interfaces, rather than letting traffic directed to the host be delivered normally?
Xen2 is way better, man. Xen3 was really poorly written, and really suffered when Singer left and Ratner had to take over.
The "suck" part is all the major changes taking place in point releases, that from their perspective arent so major but cause a major headache to the rest of us.
![[User Picture]](http://l-userpic.livejournal.com/4980108/1052633) | From: edm
2006-06-03 09:54 pm (UTC)
peth0 | (Link)
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This confused me too when I started trying to figure out where I got peth0. It's not explained as clearly as I'd have liked. What happens in the default bridge scripts is that one of the Xen virtual devices is linked into a bridge (xenbr0 by default) with the real ethernet device, and then the real ethernet device is renamed peth0, and the virtual interface is renamed eth0. This allows the same startup scripts, etc, to be used before and after starting up the xen bridge, but to refer to the Xen virtual interface (and hence the bridge) when that's appropriate. The shorewall guide to firewalling on Xen 3 is quite useful in understanding what's going on: http://www.shorewall.net/Xen.htmland the Xen My Way document by the shorewall author was also useful for hints: http://www.shorewall.net/XenMyWay.htmlEwen | |
