Hi all,
I am trying to setup a bridge with 2 interfaces attached to it in Router-1.
Interface-1: eth1 ==> EoGRE Tunnel interface(gretap) connecting to another
Router-2 where DHCP server is running.
Interface-2: eth2 ==> Trying to use DHCP to assign IP for this eth2
interface from DHCP-Server running on Router-2.
Basically the setup i am expecting is like:
(eth2)[Router-1](eth1:100.1.1.1) <----------EoGRE
Tunnel----->(eth0:100.1.1.254)[Router-2](DHCP-Server)
Following are the setup i did to check the 1st stage to see if the
dhcp-discover broadcast is going out of Router-1 over EoGRE tunnel or not.
But i am not able to achieve the same.
Can anyone please let me know what is missing here? Thanks in advance.
Router-1:
1) ip link add eogre type gretap local 100.1.1.1 remote 100.1.1.254 ==>
created gretap with endpoints.
2) ip link set eogre up ==> brought the eogre interface up.
[root at centos]# ifconfig
eogre Link encap:Ethernet HWaddr 9E:25:FC:54:7F:F2
inet6 addr: fe80::9c25:fcff:fe54:7ff2/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1462 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:6 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 b) TX bytes:492 (492.0 b)
eth1 Link encap:Ethernet HWaddr 08:00:27:3C:FB:14
inet addr:100.1.1.1 Bcast:0.0.0.0 Mask:255.255.255.0
inet6 addr: fe80::a00:27ff:fe3c:fb14/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:13 errors:0 dropped:0 overruns:0 frame:0
TX packets:40 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:1398 (1.3 KiB) TX bytes:4103 (4.0 KiB)
eth2 Link encap:Ethernet HWaddr 08:00:27:5E:7F:83
BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
3) brctl addbr br0 ==> created bridge interface
4) brctl addif br0 eogre ==> attach eogre interface to bridge
5) brctl addif br0 eth2 ==> attach eth2 interface to bridge
6) sysctl -w net.ipv6.conf.eth2.disable_ipv6=1 ==> disable ipv6 in eth2
just to avoid unwanted ipv6 signalling messages from it.
7) ifconfig eth2 up ==> eth2 iface up with no IP in it yet.
8) ifconfig eogre up ==> eogre iface up
9) ifconfig br0 up ==> Bridge up.
10) brctl show ==>
bridge name bridge id STP enabled interfaces
br0 8000.0800275e7f83 no eogre
eth2
11) brctl showstp br0
[root at centos-dev ~]# brctl showstp br0
br0
bridge id 8000.0800275e7f83
designated root 8000.0800275e7f83
root port 0 path cost 0
max age 19.99 bridge max age
19.99
hello time 1.99 bridge hello time
1.99
forward delay 14.99 bridge forward delay
14.99
ageing time 299.95
hello timer 0.50 tcn timer
0.00
topology change timer 0.00 gc timer
1.50
hash elasticity 4 hash max 512
mc last member count 2 mc init query count 2
mc router 1 mc snooping 1
mc last member timer 0.99 mc membership timer
259.96
mc querier timer 254.96 mc query interval
124.98
mc response interval 9.99 mc init query interval
31.24
flags
eogre (0)
port id 0000 state
forwarding
designated root 8000.0800275e7f83 path cost 100
designated bridge 8000.0800275e7f83 message age timer
0.00
designated port 8001 forward delay timer
0.00
designated cost 0 hold timer
0.00
mc router 1
flags
eth2 (0)
port id 0000 state
forwarding
designated root 8000.0800275e7f83 path cost 4
designated bridge 8000.0800275e7f83 message age timer
0.00
designated port 8002 forward delay timer
0.00
designated cost 0 hold timer
0.00
mc router 1
flags
12) dhclient -i eth2 ==> This command triggers a DHCP-DISCOVER
broadcast(both l2/l3 broadcast destination addressed) from eth2 and
initiate ip allocation process.
Now if i capture packets in wireshark in eth1+br0+eogre interface of
Router-1, i don't see the dhcp-discover packet sent from eth2 interface
going over EoGRE Tunnel to Router-2.
But the same DHCP-Discover packet i can see if i capture in eth2
interface(obvious reason).
Is it not like whatever packets coming in or originating from eth2 will be
bridged to eogre interface using bridge "br0"?
I am using kernel 2.6 in CentOS
Can someone please help here?
Regards,
...Balaji
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.linuxfoundation.org/pipermail/bridge/attachments/20161213/fb5b10d8/attachment.html>
Stephen Hemminger
2016-Dec-13 17:41 UTC
[Bridge] Bridge interface not forwarding DHCP-Broadcast
On Tue, 13 Dec 2016 21:13:43 +0530 Balaji J <ping2balaji at gmail.com> wrote:> Hi all, > > I am trying to setup a bridge with 2 interfaces attached to it in Router-1. > Interface-1: eth1 ==> EoGRE Tunnel interface(gretap) connecting to another > Router-2 where DHCP server is running. > Interface-2: eth2 ==> Trying to use DHCP to assign IP for this eth2 > interface from DHCP-Server running on Router-2. > > Basically the setup i am expecting is like: > (eth2)[Router-1](eth1:100.1.1.1) <----------EoGRE > Tunnel----->(eth0:100.1.1.254)[Router-2](DHCP-Server) > > Following are the setup i did to check the 1st stage to see if the > dhcp-discover broadcast is going out of Router-1 over EoGRE tunnel or not. > But i am not able to achieve the same. > > Can anyone please let me know what is missing here? Thanks in advance. > > Router-1: > 1) ip link add eogre type gretap local 100.1.1.1 remote 100.1.1.254 ==> > created gretap with endpoints. > 2) ip link set eogre up ==> brought the eogre interface up. > [root at centos]# ifconfig > eogre Link encap:Ethernet HWaddr 9E:25:FC:54:7F:F2 > inet6 addr: fe80::9c25:fcff:fe54:7ff2/64 Scope:Link > UP BROADCAST RUNNING MULTICAST MTU:1462 Metric:1 > RX packets:0 errors:0 dropped:0 overruns:0 frame:0 > TX packets:6 errors:0 dropped:0 overruns:0 carrier:0 > collisions:0 txqueuelen:1000 > RX bytes:0 (0.0 b) TX bytes:492 (492.0 b) > > eth1 Link encap:Ethernet HWaddr 08:00:27:3C:FB:14 > inet addr:100.1.1.1 Bcast:0.0.0.0 Mask:255.255.255.0 > inet6 addr: fe80::a00:27ff:fe3c:fb14/64 Scope:Link > UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 > RX packets:13 errors:0 dropped:0 overruns:0 frame:0 > TX packets:40 errors:0 dropped:0 overruns:0 carrier:0 > collisions:0 txqueuelen:1000 > RX bytes:1398 (1.3 KiB) TX bytes:4103 (4.0 KiB) > > eth2 Link encap:Ethernet HWaddr 08:00:27:5E:7F:83 > BROADCAST MULTICAST MTU:1500 Metric:1 > RX packets:0 errors:0 dropped:0 overruns:0 frame:0 > TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 > collisions:0 txqueuelen:1000 > RX bytes:0 (0.0 b) TX bytes:0 (0.0 b) > 3) brctl addbr br0 ==> created bridge interface > 4) brctl addif br0 eogre ==> attach eogre interface to bridge > 5) brctl addif br0 eth2 ==> attach eth2 interface to bridge > 6) sysctl -w net.ipv6.conf.eth2.disable_ipv6=1 ==> disable ipv6 in eth2 > just to avoid unwanted ipv6 signalling messages from it. > 7) ifconfig eth2 up ==> eth2 iface up with no IP in it yet. > 8) ifconfig eogre up ==> eogre iface up > 9) ifconfig br0 up ==> Bridge up. > 10) brctl show ==> > bridge name bridge id STP enabled interfaces > br0 8000.0800275e7f83 no eogre > > eth2 > > 11) brctl showstp br0 > > [root at centos-dev ~]# brctl showstp br0 > br0 > bridge id 8000.0800275e7f83 > designated root 8000.0800275e7f83 > root port 0 path cost 0 > max age 19.99 bridge max age > 19.99 > hello time 1.99 bridge hello time > 1.99 > forward delay 14.99 bridge forward delay > 14.99 > ageing time 299.95 > hello timer 0.50 tcn timer > 0.00 > topology change timer 0.00 gc timer > 1.50 > hash elasticity 4 hash max 512 > mc last member count 2 mc init query count 2 > mc router 1 mc snooping 1 > mc last member timer 0.99 mc membership timer > 259.96 > mc querier timer 254.96 mc query interval > 124.98 > mc response interval 9.99 mc init query interval > 31.24 > flags > > > eogre (0) > port id 0000 state > forwarding > designated root 8000.0800275e7f83 path cost 100 > designated bridge 8000.0800275e7f83 message age timer > 0.00 > designated port 8001 forward delay timer > 0.00 > designated cost 0 hold timer > 0.00 > mc router 1 > flags > > eth2 (0) > port id 0000 state > forwarding > designated root 8000.0800275e7f83 path cost 4 > designated bridge 8000.0800275e7f83 message age timer > 0.00 > designated port 8002 forward delay timer > 0.00 > designated cost 0 hold timer > 0.00 > mc router 1 > flags > > 12) dhclient -i eth2 ==> This command triggers a DHCP-DISCOVER > broadcast(both l2/l3 broadcast destination addressed) from eth2 and > initiate ip allocation process. > > Now if i capture packets in wireshark in eth1+br0+eogre interface of > Router-1, i don't see the dhcp-discover packet sent from eth2 interface > going over EoGRE Tunnel to Router-2. > But the same DHCP-Discover packet i can see if i capture in eth2 > interface(obvious reason). > > Is it not like whatever packets coming in or originating from eth2 will be > bridged to eogre interface using bridge "br0"? > I am using kernel 2.6 in CentOS > > Can someone please help here? > > Regards, > ...BalajiYou can't and shouldn't try to do anything that assigns an IP address to a device that is a member of a bridge. In your case that is eth2. The correct thing to do is run DHCP client on the bridge device.