What you observed is the expected behavior. Adding such a check will add an
overhead on l2-output with VTR configured and affect the packet forwarding
efficiency. I still don’t understand the purpose of pushing dot1ad tag on
packet at customer interface input in your VPLS test setup. It just make L2
forwarding slower because of the VLAN tag push/pop overhead on each packet and
does not serve any purpose, AFAIK. -John
From: Mehran Memarnejad <memarnejad...@gmail.com>
Sent: Sunday, May 27, 2018 8:56 AM
To: John Lo (loj) <l...@cisco.com>; vpp-dev@lists.fd.io
Subject: Re: dot1ad tag
Hi,
The patch makes it work perfectly. Now the Second tag (SPtag) is removed.
But I think there is another bug here.
First scenario:
PE1 : set interface l2 tag-rewrite GigabitEthernet5/0/0 push dot1ad 200
PE2 : set interface l2 tag-rewrite GigabitEthernet4/0/1 push dot1ad 200
Everything works perfect. the first PE adds the 802.1ad tag of 200 and the
second PE removes it.
Second scenario:
PE1 : set interface l2 tag-rewrite GigabitEthernet5/0/0 push dot1ad 200
PE2 : set interface l2 tag-rewrite GigabitEthernet4/0/1 push dot1ad 120
I expect the second PE does not pass the packet, since its tag(120) is
different from the received tag(200), (Or in other words they are in different
service provider's vlan. Am I right?)
But unfortunately, the second PE passes it.
I think that the source code is just considering the number of tags, not the
number of tags and their value. I think this is the bug. Am I right??
On Sun, May 27, 2018 at 5:18 PM, Mehran Memarnejad
<memarnejad...@gmail.com<mailto:memarnejad...@gmail.com>> wrote:
Hi,
The patch makes it work perfectly. Now the Second tag (SPtag) is removed.
But I think there is another bug here.
First scenario:
PE1 : set interface l2 tag-rewrite GigabitEthernet5/0/0 push dot1ad 200
PE2 : set interface l2 tag-rewrite GigabitEthernet4/0/1 push dot1ad 200
On Sat, May 26, 2018 at 5:51 AM, John Lo (loj)
<l...@cisco.com<mailto:l...@cisco.com>> wrote:
I just submitted a patch. Can you give it a try if this resolve the problem?
-John
https://gerrit.fd.io/r/#/c/12750/
From: Mehran Memarnejad
<memarnejad...@gmail.com<mailto:memarnejad...@gmail.com>>
Sent: Friday, May 25, 2018 1:24 PM
To: John Lo (loj) <l...@cisco.com<mailto:l...@cisco.com>>;
vpp-dev@lists.fd.io<mailto:vpp-dev@lists.fd.io>
Subject: Re: dot1ad tag
Without tag-rewrite configuration, everything works well. But I want to
activate QinQ feature, so I need to add service provider tag (sp-tag) by using
dot1ad tag.
Any more idea to solve the problem??
On Friday, May 25, 2018, John Lo (loj) <l...@cisco.com<mailto:l...@cisco.com>>
wrote:
The tag-rewrite (VTR) configuration looks right. I looked at the
l2_vtr_process() function in l2_vtr.h to check how it checks for errors. This
is the error drop path:
/* if not enough tags to pop then drop packet */
if (PREDICT_FALSE ((vnet_buffer (b0)->l2.l2_len - 12) < config->pop_bytes))
{
return 1;
}
My guess is that interface-rx-dpo-l2 node did not setup l2_len field in the
vnet buffer properly before passing the packet to l2-input node. That’s why
tag-rewrite operation on l2-output node does not function properly. If you
remove the tag rewrite config from these GigabitEthernet5/0/0 customer ports on
both PEs, I suppose it should start to work. Any reason you want to have the
additional dot1ad tag on the packets for forwarding in the BD and MPLS tunnel?
Regards,
John
From: Mehran Memarnejad
<memarnejad...@gmail.com<mailto:memarnejad...@gmail.com>>
Sent: Friday, May 25, 2018 4:40 AM
To: John Lo (loj) <l...@cisco.com<mailto:l...@cisco.com>>;
vpp-dev@lists.fd.io<mailto:vpp-dev@lists.fd.io>
Subject: Re: dot1ad tag
Sw_if_index 6 is the mpls tunnel0 and sw_if_index 3 is the GigabitEthernet5/0/0
on which I have set interface tag-rewrite push dot1ad 12 .... (both of them are
attached to bridge1)
Gigabitethernet5/0/0 is the PE's interface toward customer, meaning that I
guess if it does not drop the packet, VPLS will work.
The packet is sent to the interface attached to bridge (gigabitethernet5/0/0)
by mupls tunnel0.
But then the packet drops.
On Friday, May 25, 2018, John Lo (loj) <l...@cisco.com<mailto:l...@cisco.com>>
wrote:
Hi Mehran,
The packet trace shows drop is cause by l2-output node when the packet is sent
on the interface with sw_if_index 3 where the output tag-rewrite operation is
not expecting packet with a dot1ad tag of 12. What is the interface with
sw_if_index of 3 on that PE? Is this the same interface where you have
tag-rewrite of “push dot1ad 12” applied?
Can you provide the output of “show bridge 1 detail” (assuming bridge domain ID
of 1 is used for bd_index 1, otherwise, substitute with the ID used) on that
PE, please? The output will show all interfaces in the bridge domain with
sw_if_index and tag-rewrite operation configured on each interface.
Regards,
John
From: vpp-dev@lists.fd.io<mailto:vpp-dev@lists.fd.io>
<vpp-dev@lists.fd.io<mailto:vpp-dev@lists.fd.io>> On Behalf Of Mehran Memarnejad
Sent: Thursday, May 24, 2018 8:12 AM
To: vpp-dev@lists.fd.io<mailto:vpp-dev@lists.fd.io>
Subject: [vpp-dev] dot1ad tag
Hi,
I have configured VPLS in VPP somehow like this
link<https://lists.fd.io/g/vpp-dev/message/9112?p=,,,20,0,0,0::Created,,vpls,20,2,0,18122864>.
In addition to the above configurations, I want to add a second vlan tag i.e.
802.1ad (QinQ).
To achieve this, I entered following command in both PEs:
"Set interface l2 tag-rewrite GigabitEthernet5/0/0 push dot1ad 12"
Tracking what's going on, I found that the first PE adds the QinQ tag (12), but
the second PE will not remove this tag and afterward it goes to error node with
this message:
"l2-output: L2 output tag rewrite drops"
Here is what show trace shows in the second PE:
Packet 1
00:31:10:348251: dpdk-input
TenGigabitEthernet4/0/0 rx queue 0
buffer 0x21b6f: current data 14, length 114, free-list 0, clone-count 0,
totlen-nifb 0, trace 0x0
ext-hdr-valid
l4-cksum-computed l4-cksum-correct l2-hdr-offset 0
l3-hdr-offset 14
PKT MBUF: port 1, nb_segs 1, pkt_len 128
buf_len 2176, data_len 128, ol_flags 0x180, data_off 128, phys_addr
0x4ce6dc40
packet_type 0x1 l2_len 0 l3_len 0 outer_l2_len 0 outer_l3_len 0
rss 0x0 fdir.hi 0x0 fdir.lo 0x0
Packet Offload Flags
PKT_RX_IP_CKSUM_GOOD (0x0080) IP cksum of RX pkt. is valid
PKT_RX_L4_CKSUM_GOOD (0x0100) L4 cksum of RX pkt. is valid
Packet Types
RTE_PTYPE_L2_ETHER (0x0001) Ethernet packet
MPLS: 00:25:90:97:fa:10 -> a0:36:9f:23:aa:78
label 60 exp 0, s 0, ttl 63
00:31:10:348260: mpls-input
MPLS: next mpls-lookup[1] label 60 ttl 63 exp 0
00:31:10:348265: mpls-lookup
MPLS: next [7], lookup fib index 0, LB index 23 hash 0 label 60 eos 0
00:31:10:348268: lookup-mpls-dst
fib-index:0 hdr:[33:64:0:eos] load-balance:21
00:31:10:348270: interface-rx-dpo-l2
sw_if_index:6
00:31:10:348272: l2-input
l2-input: sw_if_index 6 dst 30:85:a9:f2:23:12 src 3c:07:71:5f:2d:f5
00:31:10:348275: l2-learn
l2-learn: sw_if_index 6 dst 30:85:a9:f2:23:12 src 3c:07:71:5f:2d:f5 bd_index 1
00:31:10:348277: l2-fwd
l2-fwd: sw_if_index 6 dst 30:85:a9:f2:23:12 src 3c:07:71:5f:2d:f5 bd_index 1
00:31:10:348280: l2-output
l2-output: sw_if_index 3 dst 30:85:a9:f2:23:12 src 3c:07:71:5f:2d:f5 data 88
a8 00 0c 81 00 00 06 08 00 45 00
00:31:10:348282: error-drop
l2-output: L2 output tag rewrite drops
Colors: Packet reception , MPLS tag handling, L2 handling, Error
If you notice red underlined trace, 802.1ad tag 12 (in hex 0C) and 802.1q tag 6
(in hex 06) has been added to packet.
I inspected the code in /src/vnet/l2/l2_vtr.h l2_vtr_process() function
and /src/vnet/l2/l2_input.h vnet_update_l2_len() function, but I couldn't
find any problem.
MY QUESTION: Is it a bug in code that the 802.1ad tag is not removed?? Or
should I have entered more commands?
Thanks in advance
