[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: Bridging klappt nicht



Stefan Bauer schrieb:
Arnd Münzebrock schrieb:
Ok, traffic gibts also auch auf tap0, dann sollte ja auch eine dhcp-Anfrage funktionieren. Tut sie aber nicht:

chef:/home/moritz# tcpdump -i tap0
tcpdump: WARNING: tap0: no IPv4 address assigned
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on tap0, link-type EN10MB (Ethernet), capture size 96 bytes
18:52:08.002762 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from 00:ff:f8:de:7e:8b (oui Unknown), length 300 18:52:23.002085 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from 00:ff:f8:de:7e:8b (oui Unknown), length 300

Die DHCP Anfrage geht als DHCP Discover Paket per Broadcast raus. Absender 0.0.0.0 Empfänger Alle. Antworten gibt es jedoch keine vom DHCP-Server.

Läuft tun0 im promiscious modus? dmesg verräts. Sonst dem ifconfig Befehl noch promisc mitgeben.

Du meinst tap0? Habe ich probiert, aber selbst mit tap0 und eth1 (meine reale NIC) im promiscous mode bekomme ich keine Antwort vom dhcp-server:

chef:/home/moritz# tunctl -u moritz -t tap0
Set 'tap0' persistent and owned by uid 1000
chef:/home/moritz# ip addr show
1: lo: <LOOPBACK,UP,10000> 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 scope host lo
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: eth1: <BROADCAST,MULTICAST,PROMISC,UP,10000> mtu 1500 qdisc pfifo_fast qlen 1000
    link/ether 00:1d:92:63:42:16 brd ff:ff:ff:ff:ff:ff
    inet6 fe80::21d:92ff:fe63:4216/64 scope link
       valid_lft forever preferred_lft forever
4: br0: <BROADCAST,MULTICAST,UP,10000> mtu 1500 qdisc noqueue
    link/ether 00:1d:92:63:42:16 brd ff:ff:ff:ff:ff:ff
    inet 192.168.178.32/24 brd 192.168.178.255 scope global br0
    inet6 fe80::21d:92ff:fe63:4216/64 scope link
       valid_lft forever preferred_lft forever
5: tap0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop qlen 500
    link/ether 00:ff:39:b7:ef:8a brd ff:ff:ff:ff:ff:ff
chef:/home/moritz# brctl addif br0 tap0
chef:/home/moritz# ifconfig tap0 promisc up
chef:/home/moritz# ip addr show
1: lo: <LOOPBACK,UP,10000> 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 scope host lo
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: eth1: <BROADCAST,MULTICAST,PROMISC,UP,10000> mtu 1500 qdisc pfifo_fast qlen 1000
    link/ether 00:1d:92:63:42:16 brd ff:ff:ff:ff:ff:ff
    inet6 fe80::21d:92ff:fe63:4216/64 scope link
       valid_lft forever preferred_lft forever
4: br0: <BROADCAST,MULTICAST,UP,10000> mtu 1500 qdisc noqueue
    link/ether 00:1d:92:63:42:16 brd ff:ff:ff:ff:ff:ff
    inet 192.168.178.32/24 brd 192.168.178.255 scope global br0
    inet6 fe80::21d:92ff:fe63:4216/64 scope link
       valid_lft forever preferred_lft forever
5: tap0: <BROADCAST,MULTICAST,PROMISC,UP,10000> mtu 1500 qdisc pfifo_fast qlen 500
    link/ether 00:ff:39:b7:ef:8a brd ff:ff:ff:ff:ff:ff
    inet6 fe80::2ff:39ff:feb7:ef8a/64 scope link
       valid_lft forever preferred_lft forever
chef:/home/moritz# brctl show br0
bridge name     bridge id               STP enabled     interfaces
br0 8000.001d92634216 no can't get port info: Operation not supported
chef:/home/moritz# brctl showmacs br0
port no mac addr                is local?       ageing timer
  1     00:04:0e:XX:XX:XX       no                 0.05
  1     00:1d:92:63:42:16       yes                0.00
  1     00:40:05:XX:XX:XX       no                 0.89
  2     00:ff:39:b7:ef:8a       yes                0.00
chef:/home/moritz# dhclient tap0
Internet Systems Consortium DHCP Client V3.0.4
Copyright 2004-2006 Internet Systems Consortium.
All rights reserved.
For info, please visit http://www.isc.org/sw/dhcp/

Listening on LPF/tap0/00:ff:39:b7:ef:8a
Sending on   LPF/tap0/00:ff:39:b7:ef:8a
Sending on   Socket/fallback
DHCPDISCOVER on tap0 to 255.255.255.255 port 67 interval 8
DHCPDISCOVER on tap0 to 255.255.255.255 port 67 interval 14
DHCPDISCOVER on tap0 to 255.255.255.255 port 67 interval 14
DHCPDISCOVER on tap0 to 255.255.255.255 port 67 interval 19
DHCPDISCOVER on tap0 to 255.255.255.255 port 67 interval 6
No DHCPOFFERS received.
No working leases in persistent database - sleeping.

Interessanterweise funktioniert es umgekehrt; Die DHCP-Anforderung von br0 und die Antwort von der FritzBox schaffen es bis auf tap0:

chef:/home/moritz# tcpdump -i eth1 portrange 67-68
tcpdump: WARNING: eth1: no IPv4 address assigned
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth1, link-type EN10MB (Ethernet), capture size 96 bytes
17:37:05.902263 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from 00:1d:92:63:42:16 (oui Unknown), length 300 17:37:05.936777 IP 192.168.178.1.bootps > 255.255.255.255.bootpc: BOOTP/DHCP, Reply, length 548

2 packets captured
2 packets received by filter
0 packets dropped by kernel
chef:/home/moritz# tcpdump -i tap0 portrange 67-68
tcpdump: WARNING: tap0: no IPv4 address assigned
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on tap0, link-type EN10MB (Ethernet), capture size 96 bytes
17:37:44.003347 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from 00:1d:92:63:42:16 (oui Unknown), length 300 17:37:44.036319 IP 192.168.178.1.bootps > 255.255.255.255.bootpc: BOOTP/DHCP, Reply, length 548

Auch eine DHCP-Anfrage vo einem anderen Rechner (moritz) schafft es bis auf tap0.

Etwas mehr Informationen zu deinem restlichen Netzwerk wären auch interessant.

Relativ simpel:

[MacMini] <--WLAN--> [FritzBox] <--LAN------> [moritz (Debian testing)]
                                        \---> [chef (Debian stable)]

Was gibt ein brctl show br0 aus?

Wenig:

chef:/home/moritz# brctl show br0
bridge name     bridge id               STP enabled     interfaces
br0 8000.001d92634216 no can't get port info: Operation not supported

Noch ein paar Angaben zu meinem System:

wie gesagt Debian stable mit backports
Linux chef 2.6.22-4-amd64 #1 SMP Tue Feb 12 20:38:49 UTC 2008 x86_64
AMD Athlon 64 X2 5200+
MSI K9AG Neo2 mit AMD 690G Chipsatz

Gruß,
	Arnd

--

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Arnd Münzebrock                                    Arnd@nurfuerspam.de
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Seit ich das Alphabet kenne, versuche ich es zu benutzen...


Reply to: