[ovs-discuss] TCP tunnel traffic stops working when move from RHEL 7.7 to 7.9
Brendan Doyle
brendan.doyle at oracle.com
Thu Apr 29 09:54:49 UTC 2021
Hi Folks,
In a very basic OVN config, where I have two VMs on different chassis:
switch 7b89d593-05f3-41a7-a246-8dade975df48 (ls_vcn1)
port a6a358c5-5db4-49c7-b68a-3a7429161ab4
addresses: ["52:54:00:71:ad:a0 192.16.1.5"]
port b6c5ef1a-acd9-4053-9986-88e1a6a12b81
addresses: ["52:54:00:40:8f:dc 192.16.1.6"]
When I upgrade the chassis from OEL 7.7 (RHEL 7.7 based) to OEL 7.9
(RHEL 7.9) based, then
TCP traffic stops working, ping and UDP are fine. When I look at tcpdump
of the traffic on both
chassis, I see the initial handshake encapsulated traffic being sent and
revived on both nodes.
The initial TCP handshake seems to get through on the sender and it
sends the first data packet
but the receive side does not get the data packets and keeps sending
the initial handshake ack
(see traces below).
I'm think something to do with tcp checksum or some other NIC offload?
the NICS are CX5s.
Just wondering has anyone come across this?
Thanks
Brendan
Sender
---------
98:03:9b:89:21:e2 > 98:03:9b:89:21:5a, ethertype IPv4 (0x0800), length
132: (tos 0x0, ttl 64, id 29694, offset 0, flags [DF], proto UDP (17),
length 118)
253.255.0.21.62384 > 253.255.0.18.6081: [bad udp cksum 0xfc99 ->
0xa576!] Geneve, Flags [C], vni 0x1, proto TEB (0x6558), options [class
Open Virtual Networking (OVN) (0x102) type 0x80(C) len 8 data 00010002]
52:54:00:40:8f:dc > 52:54:00:71:ad:a0, ethertype IPv4 (0x0800),
length 74: (tos 0x0, ttl 64, id 61068, offset 0, flags [DF], proto TCP
(6), length 60)
192.16.1.6.38900 > 192.16.1.5.22: Flags [S], cksum 0x0a2b
(correct), seq 3225335796, win 27200, options [mss 1360,sackOK,TS val
1242625918 ecr 0,nop,wscale 7], length 0
98:03:9b:89:21:5a > 98:03:9b:89:21:e2, ethertype IPv4 (0x0800), length
132: (tos 0x0, ttl 64, id 5167, offset 0, flags [DF], proto UDP (17),
length 118)
253.255.0.18.28454 > 253.255.0.21.6081: [udp sum ok] Geneve, Flags
[C], vni 0x1, proto TEB (0x6558), options [class Open Virtual Networking
(OVN) (0x102) type 0x80(C) len 8 data 00020001]
52:54:00:71:ad:a0 > 52:54:00:40:8f:dc, ethertype IPv4 (0x0800),
length 74: (tos 0x0, ttl 64, id 0, offset 0, flags [DF], proto TCP (6),
length 60)
192.16.1.5.22 > 192.16.1.6.38900: Flags [S.], cksum 0xb82f
(correct), seq 3217262113, ack 3225335797, win 26960, options [mss
1360,sackOK,TS val 3343009202 ecr 1242625918,nop,wscale 7], length 0
98:03:9b:89:21:e2 > 98:03:9b:89:21:5a, ethertype IPv4 (0x0800), length
124: (tos 0x0, ttl 64, id 29695, offset 0, flags [DF], proto UDP (17),
length 110)
253.255.0.21.62384 > 253.255.0.18.6081: [bad udp cksum 0xa57e ->
0x723d!] Geneve, Flags [C], vni 0x1, proto TEB (0x6558), options [class
Open Virtual Networking (OVN) (0x102) type 0x80(C) len 8 data 00010002]
52:54:00:40:8f:dc > 52:54:00:71:ad:a0, ethertype IPv4 (0x0800),
length 66: (tos 0x0, ttl 64, id 61069, offset 0, flags [DF], proto TCP
(6), length 52)
192.16.1.6.38900 > 192.16.1.5.22: Flags [.], cksum 0x8252
(incorrect -> 0x4f11), seq 1, ack 1, win 213, options [nop,nop,TS val
1242625920 ecr 3343009202], length 0
98:03:9b:89:21:e2 > 98:03:9b:89:21:5a, ethertype IPv4 (0x0800), length
145: (tos 0x0, ttl 64, id 29696, offset 0, flags [DF], proto UDP (17),
length 131)
253.255.0.21.62384 > 253.255.0.18.6081: [bad udp cksum 0xa569 ->
0xae4d!] Geneve, Flags [C], vni 0x1, proto TEB (0x6558), options [class
Open Virtual Networking (OVN) (0x102) type 0x80(C) len 8 data 00010002]
52:54:00:40:8f:dc > 52:54:00:71:ad:a0, ethertype IPv4 (0x0800),
length 87: (tos 0x0, ttl 64, id 61070, offset 0, flags [DF], proto TCP
(6), length 73)
192.16.1.6.38900 > 192.16.1.5.22: Flags [P.], cksum 0x8267
(incorrect -> 0x8b4b), seq 1:22, ack 1, win 213, options [nop,nop,TS val
1242625920 ecr 3343009202], length 21
98:03:9b:89:21:e2 > 98:03:9b:89:21:5a, ethertype IPv4 (0x0800), length
145: (tos 0x0, ttl 64, id 29775, offset 0, flags [DF], proto UDP (17),
length 131)
253.255.0.21.62384 > 253.255.0.18.6081: [bad udp cksum 0xa569 ->
0xad7f!] Geneve, Flags [C], vni 0x1, proto TEB (0x6558), options [class
Open Virtual Networking (OVN) (0x102) type 0x80(C) len 8 data 00010002]
52:54:00:40:8f:dc > 52:54:00:71:ad:a0, ethertype IPv4 (0x0800),
length 87: (tos 0x0, ttl 64, id 61071, offset 0, flags [DF], proto TCP
(6), length 73)
192.16.1.6.38900 > 192.16.1.5.22: Flags [P.], cksum 0x8267
(incorrect -> 0x8a7d), seq 1:22, ack 1, win 213, options [nop,nop,TS val
1242626126 ecr 3343009202], length 21
Just repeats don't see anything else from the receiver
Receiver
------------
98:03:9b:89:21:e2 > 98:03:9b:89:21:5a, ethertype IPv4 (0x0800), length
132: (tos 0x0, ttl 64, id 29694, offset 0, flags [DF], proto UDP (17),
length 118)
253.255.0.21.62384 > 253.255.0.18.6081: [udp sum ok] Geneve, Flags
[C], vni 0x1, proto TEB (0x6558), options [class Open Virtual Networking
(OVN) (0x102) type 0x80(C) len 8 data 00010002]
52:54:00:40:8f:dc > 52:54:00:71:ad:a0, ethertype IPv4 (0x0800),
length 74: (tos 0x0, ttl 64, id 61068, offset 0, flags [DF], proto TCP
(6), length 60)
192.16.1.6.38900 > 192.16.1.5.22: Flags [S], cksum 0x0a2b
(correct), seq 3225335796, win 27200, options [mss 1360,sackOK,TS val
1242625918 ecr 0,nop,wscale 7], length 0
98:03:9b:89:21:5a > 98:03:9b:89:21:e2, ethertype IPv4 (0x0800), length
132: (tos 0x0, ttl 64, id 5167, offset 0, flags [DF], proto UDP (17),
length 118)
253.255.0.18.28454 > 253.255.0.21.6081: [bad udp cksum 0xfc99 ->
0x2a01!] Geneve, Flags [C], vni 0x1, proto TEB (0x6558), options [class
Open Virtual Networking (OVN) (0x102) type 0x80(C) len 8 data 00020001]
52:54:00:71:ad:a0 > 52:54:00:40:8f:dc, ethertype IPv4 (0x0800),
length 74: (tos 0x0, ttl 64, id 0, offset 0, flags [DF], proto TCP (6),
length 60)
192.16.1.5.22 > 192.16.1.6.38900: Flags [S.], cksum 0xb82f
(correct), seq 3217262113, ack 3225335797, win 26960, options [mss
1360,sackOK,TS val 3343009202 ecr 1242625918,nop,wscale 7], length 0
98:03:9b:89:21:5a > 98:03:9b:89:21:e2, ethertype IPv4 (0x0800), length
132: (tos 0x0, ttl 64, id 6137, offset 0, flags [DF], proto UDP (17),
length 118)
253.255.0.18.28454 > 253.255.0.21.6081: [bad udp cksum 0x2a01 ->
0x5bc0!] Geneve, Flags [C], vni 0x1, proto TEB (0x6558), options [class
Open Virtual Networking (OVN) (0x102) type 0x80(C) len 8 data 00020001]
52:54:00:71:ad:a0 > 52:54:00:40:8f:dc, ethertype IPv4 (0x0800),
length 74: (tos 0x0, ttl 64, id 0, offset 0, flags [DF], proto TCP (6),
length 60)
192.16.1.5.22 > 192.16.1.6.38900: Flags [S.], cksum 0x825a
(incorrect -> 0xb419), seq 3217262113, ack 3225335797, win 26960,
options [mss 1360,sackOK,TS val 3343010248 ecr 1242625918,nop,wscale 7],
length 0
Repeats don't see anything else from the sender.
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