Re: [mpls-linux-general] Packet getting lost after push

[James R. L. <jl...@mi...>]

On Tue, Dec 18, 2001 at 12:39:42AM -0800, Amit Kulkarni wrote:
> Hi all,
> 
> I am using mpls functions in my code .How ever when I
> try to push a label on the packet, the next hop does
> not get it. Strangely in the first machine  packet
> transmitted count is incremented and some printks show
> the packet goes till the driver interface.On the other
> machine however there is no action in the
> net_rx_action function in  net/core/dev.c 

Are you sure you specified a valid nexthop?

> Did anybody face similar such problem before ?

No.

> can somebody give me pointers ??
> I am attaching the skb_dump of the packet before and
> after the pushing the label.
> I will be happy to provide you any other information
> you need.

Exactly what calls did you make to setup this LSP?

> also I was wondering if theres any particular reason
> why you are not  doing 
> skb->nh.ar_pro = __constant_htons_(ETH_P_MPLS_UC) or

Because just before dev_queue_xmit() the L2 header in the skb is
overwritten with the L2 header from the neighbor table.  The neighbor
table creates a neighbor entry by looking at skb->protocol ...

Jim

> similar such thing 
> 
> thanks in advance 
> Amit
> 
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Content-Description: Temp.out
> skb_dump: from eth2 with len 124 (324) headroom=18 tailroom=18
> 000000000000000000000000000000000000{*000102494d30000102494eae0800#|4540006e091c00003f0455d90a05041e0a03043200000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000ac200200010000091c01a552ebfe5aad14fe}
> mpls_opcode_push: using tailroom
> mpls_opcode_push: done using tailroom
> mpls_opcode_push: dump after tail room new packet
> skb_dump: from eth2 with len 128 (324) headroom=18 tailroom=14
> 000000000000000000000000000000000000{*00010249000102494d3000010249#|4eae08004540006e091c00003f0455d90a05041e0a03043200000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000ac200200010000091c01a552ebfe5aad1400}

-- 
James R. Leu
jl...@mi...