Hi Daniel,
Really thanks for your hints and it is really the checksum errors.
When I ssh from PC ( 192.168.21.100) in Wan to domU in xbrdmz0, it has
checksum errors. It causes me not able to use ssh.
-------------------------------------------------------------
[root@jssrv01 conf]# tcpdump -v -n host 192.168.21.15
tcpdump: WARNING: eth0: no IPv4 address assigned
tcpdump: listening on eth0, link-type EN10MB (Ethernet), capture size 96
bytes
00:13:01.797379 IP (tos 0x0, ttl 128, id 25066, offset 0, flags [DF], proto
6, length: 48) 192.168.21.100.1521 > 192.168.21.15.ssh: S [tcp s
um ok] 4291786245:4291786245(0) win 65535 <mss 1460,nop,nop,sackOK>
00:13:01.798189 IP (tos 0x0, ttl 63, id 0, offset 0, flags [DF], proto 6,
length: 48) 192.168.21.15.ssh > 192.168.21.100.1521: S [tcp sum o
k] 2137667989:2137667989(0) ack 4291786246 win 5840 <mss
1460,nop,nop,sackOK>
00:13:01.798364 IP (tos 0x0, ttl 128, id 25067, offset 0, flags [DF], proto
6, length: 40) 192.168.21.100.1521 > 192.168.21.15.ssh: . [tcp s
um ok] ack 1 win 65535
00:13:01.823132 IP (tos 0x0, ttl 63, id 48214, offset 0, flags [DF], proto
6, length: 60) 192.168.21.15.ssh > 192.168.21.100.1521: P [bad t
cp cksum 3a1 (->5a1)!] 1:21(20) ack 1 win 5840
00:13:04.816419 IP (tos 0x0, ttl 63, id 48216, offset 0, flags [DF], proto
6, length: 60) 192.168.21.15.ssh > 192.168.21.100.1521: P [bad t
cp cksum 3a1 (->5a1)!] 1:21(20) ack 1 win 5840
00:13:08.706572 IP (tos 0x0, ttl 63, id 27133, offset 0, flags [DF], proto
6, length: 60) 192.168.21.15.ssh > 192.168.21.100.1520: P [bad t
cp cksum b307 (->b507)!] 2129139235:2129139255(20) ack 731365070 win 5840
00:13:10.816417 IP (tos 0x0, ttl 63, id 48218, offset 0, flags [DF], proto
6, length: 60) 192.168.21.15.ssh > 192.168.21.100.1521: P [bad t
cp cksum 3a1 (->5a1)!] 1:21(20) ack 1 win 5840
00:13:22.816419 IP (tos 0x0, ttl 63, id 48220, offset 0, flags [DF], proto
6, length: 60) 192.168.21.15.ssh > 192.168.21.100.1521: P [bad tcp cksum 3a1
(->5a1)!] 1:21(20) ack 1 win 5840
00:13:32.706490 IP (tos 0x0, ttl 63, id 27135, offset 0, flags [DF], proto
6, length: 60) 192.168.21.15.ssh > 192.168.21.100.1520: P [bad tcp cksum
b307 (->b507)!] 0:20(20) ack 1 win 5840
00:13:46.816434 IP (tos 0x0, ttl 63, id 48222, offset 0, flags [DF], proto
6, length: 60) 192.168.21.15.ssh > 192.168.21.100.1521: P [bad tcp cksum 3a1
(->5a1)!] 1:21(20) ack 1 win 5840
However, as said before, if I don't create the xbrwan0 and use eth0 instead.
I can ssh from PC in Wan to domU.
The tcpdump shows as follows: (PC and domU talks perfectly to each other).
------------------------------------------
[root@jssrv01 conf]# tcpdump -v -n host 192.168.21.15
tcpdump: listening on eth0, link-type EN10MB (Ethernet), capture size 96
bytes
00:24:39.154125 IP (tos 0x0, ttl 128, id 29657, offset 0, flags [DF], proto
6, length: 48) 192.168.21.100.support > 192.168.21.15.ssh: S [tcp sum ok]
3072641878:3072641878(0) win 65535 <mss 1460,nop,nop,sackOK>
00:24:39.154804 IP (tos 0x0, ttl 63, id 0, offset 0, flags [DF], proto 6,
length: 48) 192.168.21.15.ssh > 192.168.21.100.support: S [tcp sum ok]
2802605415:2802605415(0) ack 3072641879 win 5840 <mss 1460,nop,nop,sackOK>
00:24:39.155017 IP (tos 0x0, ttl 128, id 29658, offset 0, flags [DF], proto
6, length: 40) 192.168.21.100.support > 192.168.21.15.ssh: . [tcp sum ok]
ack 1 win 65535
00:24:39.195572 IP (tos 0x0, ttl 63, id 57410, offset 0, flags [DF], proto
6, length: 60) 192.168.21.15.ssh > 192.168.21.100.support: P [bad tcp cksum
abf2 (->ad7e)!] 1:21(20) ack 1 win 5840
00:24:39.200501 IP (tos 0x0, ttl 128, id 29661, offset 0, flags [DF], proto
6, length: 68) 192.168.21.100.support > 192.168.21.15.ssh: P [tcp sum ok]
1:29(28) ack 21 win 65515
00:24:39.201187 IP (tos 0x0, ttl 63, id 57412, offset 0, flags [DF], proto
6, length: 40) 192.168.21.15.ssh > 192.168.21.100.support: . [tcp sum ok]
ack 29 win 5840
00:24:39.205163 IP (tos 0x0, ttl 63, id 57414, offset 0, flags [DF], proto
6, length: 680) 192.168.21.15.ssh > 192.168.21.100.support: P 21:661(640)
ack 29 win 5840
00:24:39.210997 IP (tos 0x0, ttl 128, id 29665, offset 0, flags [DF], proto
6, length: 528) 192.168.21.100.support > 192.168.21.15.ssh: P 29:517(488)
ack 661 win 64875
00:24:39.211064 IP (tos 0x0, ttl 128, id 29666, offset 0, flags [DF], proto
6, length: 56) 192.168.21.100.support > 192.168.21.15.ssh: P [tcp sum ok]
517:533(16) ack 661 win 64875
00:24:39.249606 IP (tos 0x0, ttl 63, id 57416, offset 0, flags [DF], proto
6, length: 40) 192.168.21.15.ssh > 192.168.21.100.support: . [tcp sum ok]
ack 533 win 5840
00:24:39.258471 IP (tos 0x0, ttl 63, id 57418, offset 0, flags [DF], proto
6, length: 320) 192.168.21.15.ssh > 192.168.21.100.support: P 661:941(280)
ack 533 win 5840
00:24:39.372868 IP (tos 0x0, ttl 128, id 29670, offset 0, flags [DF], proto
6, length: 40) 192.168.21.100.support > 192.168.21.15.ssh: . [tcp sum ok]
ack 941 win 64595
00:24:39.551000 IP (tos 0x0, ttl 128, id 29672, offset 0, flags [DF], proto
6, length: 312) 192.168.21.100.support > 192.168.21.15.ssh: P 533:805(272)
ack 941 win 64595
Though the problem is located, I still don't know how to fix it...( I will
search the list for any findings..)
But....Just wonder Daniel has any further hints for me.... ;->
As I said before, I am new to Xen. This configuration is just an outcome of
trial and error.
I remember I initially use the default Xen configuration and has some
problems (I cannot remember is it exactly the same as this one or not).
Then, I change the configuration bit by bit and finally down this situation.
I am happy to stick with Xen default. As Fernando gives me some reference, I
will also check if it suit my target configuration.
Hong...
----- Original Message -----
From: "Daniel Goertzen" <goertzen@xxxxxxxx>
To: "Hong @ gmail" <whtsang22@xxxxxxxxx>
Cc: "Xen-users" <xen-users@xxxxxxxxxxxxxxxxxxx>
Sent: Saturday, January 28, 2006 10:59 PM
Subject: Re: [Xen-users] How to setup Xen for 3 bridges environment?
Hong, I don't grasp the full complexity of what you're trying to do, but I
note that you are bypassing the vif0.x/veth0.x interfaces in dom0 which
bypasses some special xen networking magic. Instead of assigning ip
addresses directly to xbrwan0, add vif0.0 to xbrwan0 and assign the
addresses to veth0. Likewise for the other bridges.
Search the list tcp checksum errors for more info on this.
Cheers,
Dan.
Hong @ gmail wrote:
Hi Fernando Maior,
Thanks for your information. I have a quick look on the Wiki document,
but find that it is a bit different from my current setup.
In my setup, I create 3 bridges in dom0 and dom0 also act as the
firewall.
Following is the summary of my configuration:
1) I by-pass the Xen bridge.
- comment out the '(network-script network-bridge)' and '(vif-script
vif-bridge)' in 'xend-config.sxp'
- comment out the 'handle_iptable' in vif-bridge.
2) Create my own 3 bridges as follows:
#
# xbrwan0 (Wan bridge)
#
ip link set eth0 down
ip addr flush eth0
brctl addbr xbrwan0
brctl stp xbrwan0 off
brctl setfd xbrwan0 0
ip addr add 192.168.21.11/24 dev xbrwan0 brd + (the xbrwan0 bridge
ip)
ip addr add 192.168.21.15/24 dev xbrwan0 brd + (NAT ip to
192.168.22.15)
ip addr add 192.168.21.16/24 dev xbrwan0 brd + (NAT ip to
192.168.22.16)
sleep 2
brctl addif xbrwan0 eth0
ifconfig eth0 0.0.0.0 up
ip link set xbrwan0 up
#
# xbrdmz0 (Dmz bridge)
#
brctl addbr xbrdmz0
brctl stp xbrdmz0 off
brctl setfd xbrdmz0 0
ifconfig xbrdmz0 192.168.22.11 netmask 255.255.255.0 up (the Dmz bridge
ip)
#
# xbrlan0 (Lan bridge)
#
brctl addbr xbrlan0
brctl stp xbrlan0 off
brctl setfd xbrlan0 0
ifconfig xbrlan0 192.168.23.11 netmask 255.255.255.0 up (the Lan bridge
ip)
3) Start two domU with ip 15 and 16
xm create domU01 (ip 192.168.21.15)
xm create domU02 (ip 192.168.21.16)
4) Create the NAT tables.
#
iptables -X
iptables -F
iptables -X -t nat
iptables -F -t nat
iptables -t nat -A PREROUTING -i xbrwan0 -d 192.168.21.15 -j DNAT --to
192.168.22.15
iptables -t nat -A POSTROUTING -o xbrwan0 -s 192.168.22.15 -j SNAT --to
192.168.21.15
iptables -t nat -A PREROUTING -i xbrwan0 -d 192.168.21.16 -j DNAT --to
192.168.22.16
iptables -t nat -A POSTROUTING -o xbrwan0 -s 192.168.22.16 -j SNAT --to
192.168.21.16
sysctl -w net.ipv4.ip_forward=1
In above setup, I ssh from Pc in Wan to domU01 and domU02.
If I didn't create the Wan bridge, instead using the eth0, I can ssh from
PC in Wan to domU01 and domU02.
=========================================================================
Following is the ifconfig and brctl show result.
[root@jssrv01 conf]# ifconfig
eth0 Link encap:Ethernet HWaddr 00:0D:0B:A7:2F:88
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:4710 errors:0 dropped:0 overruns:0 frame:0
TX packets:4760 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:717399 (700.5 KiB) TX bytes:469146 (458.1 KiB)
Interrupt:5 Base address:0xe800
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:16436 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:0
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
vif1.0 Link encap:Ethernet HWaddr FE:FF:FF:FF:FF:FF
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:33 errors:0 dropped:0 overruns:0 frame:0
TX packets:451 errors:0 dropped:22 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:2418 (2.3 KiB) TX bytes:27310 (26.6 KiB)
vif2.0 Link encap:Ethernet HWaddr FE:FF:FF:FF:FF:FF
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:53 errors:0 dropped:0 overruns:0 frame:0
TX packets:434 errors:0 dropped:27 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:3740 (3.6 KiB) TX bytes:25916 (25.3 KiB)
xbrdmz0 Link encap:Ethernet HWaddr FE:FF:FF:FF:FF:FF
inet addr:192.168.22.11 Bcast:192.168.22.255
Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:86 errors:0 dropped:0 overruns:0 frame:0
TX packets:32 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:4954 (4.8 KiB) TX bytes:2208 (2.1 KiB)
xbrlan0 Link encap:Ethernet HWaddr 00:00:00:00:00:00
inet addr:192.168.23.11 Bcast:192.168.23.255
Mask:255.255.255.0
UP BROADCAST RUNNING 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:0
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
xbrwan0 Link encap:Ethernet HWaddr 00:0D:0B:A7:2F:88
inet addr:192.168.21.11 Bcast:192.168.21.255
Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:4709 errors:0 dropped:0 overruns:0 frame:0
TX packets:4049 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:646686 (631.5 KiB) TX bytes:416226 (406.4 KiB)
and brctl show result:
[root@jssrv01 conf]# brctl show
bridge name bridge id STP enabled interfaces
xbrdmz0 8000.feffffffffff no vif1.0
vif2.0
xbrlan0 8000.feffffffffff no vif3.0
xbrwan0 8000.000d0ba72f88 no eth0
Thanks
----- Original Message ----- From: "Fernando Maior"
<fernando.souto.maior@xxxxxxxxx>
To: "Hong @ gmail" <whtsang22@xxxxxxxxx>; "Xen-users"
<xen-users@xxxxxxxxxxxxxxxxxxx>
Sent: Friday, January 27, 2006 7:28 PM
Subject: Re: [Xen-users] How to setup Xen for 3 bridges environment?
Hong,
Did you have a look at Xen wiki documentation? You may
compare http://wiki.xensource.com/xenwiki/XenNetworkingSuse
to your experience and try something like that.
On 1/26/06, Hong @ gmail <whtsang22@xxxxxxxxx> wrote:
Hello,
I am new to Xen and is trying a confugration that simulates a firewall
environment.
My target environment is to setup three bridges: one for Wan (xen-br0),
one
for DMZ (xbrdmz) and one for Lan (xbrlan)
The three subnet are as follows:
Wan: 192.168.21.0/24
Dmz: 192.168.22.0/24
Lan: 192.168.23.0/24
I use xen3.0 and FC4 for both dom0 and domU.
My machine currently has one Nic, eth0, and I ensalve it into the Wan
bridge
xen-br0.
Dom0 has the IP address 192.168.21.11. I have two domU in DMZ with IP
192.168.22.15, 192.168.22.16).
I use NAT 192.168.21.15 -> 192.168.22.15 and 192.168.21.16 ->
192.168.22.16
so that the PC from Wan can access the PC.
Most of the things work fine. I can ping dom0 and the two domU and vice
versa. I can ssh from dom0 and domU and vice versa and I can ssh from PC
on
Wan to dom0.
The only problem is that I cannot ssh from PC on Wan to domU.
I have tried another setup. If I don't use the Wan bridge ( xen-br0 )
and
just use the eth0 and the Dmz bridge (xbrdmz), everything works
perfectly.
(I can ssh from PC on Wan to domU also).
However, I still want to have the Wan bridge cause I can add some domU
in
Wan subnet (so that I can say, add some IDS domU to Wan bridge).
I have searched the mailing list and find a similar case is:
http://lists.xensource.com/archives/html/xen-users/2005-06/msg00669.html
I have tried the NOTRACK option but still can help in my case.
Just wonder anyone has setup similar environment?
Thanks alot.
_______________________________________________
Xen-users mailing list
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http://lists.xensource.com/xen-users
--
Bye,
Fernando Maior
LPIC/1(31908)
LinuxCounter(391325)
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