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> 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>
> *Sent:* Friday, May 25, 2018 4:40 AM
> *To:* John Lo (loj) <l...@cisco.com>; 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> 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 <vpp-dev@lists.fd.io> *On Behalf Of *Mehran
> Memarnejad
> *Sent:* Thursday, May 24, 2018 8:12 AM
> *To:* 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
>
>
>
>
