P4 switches not identifying packets as valid Ipv6 packets

[Debobroto Das]

Hello Everyone,

I am simulating a network using mininet. And the switches are implemented in P4. I am using the bmv2 simulator. 

But unfortunately when I run the simulation the p4 switches (stratum bmv2 switches), not identifies the packets as valid ipv6 packet.

To make sure I have added 4 extra exact matching tables,  2 with key to ipv6 src and dst address and 2 with eth src address and dest address. 

table tab1 {
key = {
hdr.ethernet.src_addr: exact;
}
actions = { NoAction; }
}
table tab2 {
key = {
hdr.ethernet.dst_addr: exact;
}
actions = { NoAction; }
}
table tab3 {
key = {
hdr.ipv6.src_addr: exact;
}
actions = { NoAction; }
}
table tab4 {
key = {
hdr.ipv6.dst_addr: exact;
}
actions = { NoAction; }
}

I have enabled debug logs in stratum_bmv2 switches. A sample log is following: I am trying 

mininet> h1p0l0 ping h2p0l0

PING 2001:1:1:1:0000:11:0000:0002(2001:1:1:1:0:11:0:2) 56 data bytes

Both of the switches are connected to p0l0.  Now when I check the logs of this switch I do not see the relevant IPv6 src and destination address. 

an example log is following:

[18:40:21.963] [bmv2] [D] [thread 23828] [934.0] [cxt 0] Table 'tbl_act': miss

[18:40:21.963] [bmv2] [D] [thread 23828] [934.0] [cxt 0] Action entry is act - 

[18:40:21.963] [bmv2] [D] [thread 23828] [934.0] [cxt 0] Looking up key:

* hdr.ethernet.src_addr: 665d6d419006

[18:40:21.963] [bmv2] [D] [thread 23828] [934.0] [cxt 0] Table 'IngressPipeImpl.tab1': miss

[18:40:21.963] [bmv2] [D] [thread 23828] [934.0] [cxt 0] Action entry is NoAction - 

[18:40:21.963] [bmv2] [D] [thread 23828] [934.0] [cxt 0] Looking up key:

* hdr.ethernet.dst_addr: 3333ff000000

[18:40:21.963] [bmv2] [D] [thread 23828] [934.0] [cxt 0] Table 'IngressPipeImpl.tab2': miss

[18:40:21.963] [bmv2] [D] [thread 23828] [934.0] [cxt 0] Action entry is NoAction - 

[18:40:21.963] [bmv2] [D] [thread 23828] [934.0] [cxt 0] Looking up key:

* hdr.ipv6.src_addr   : fe80000000000000645d6dfffe419006

[18:40:21.963] [bmv2] [D] [thread 23828] [934.0] [cxt 0] Table 'IngressPipeImpl.tab3': miss

[18:40:21.963] [bmv2] [D] [thread 23828] [934.0] [cxt 0] Action entry is NoAction - 

[18:40:21.963] [bmv2] [D] [thread 23828] [934.0] [cxt 0] Looking up key:

* hdr.ipv6.dst_addr   : ff0200000000000000000001ff000000

[18:40:21.963] [bmv2] [D] [thread 23828] [934.0] [cxt 0] Table 'IngressPipeImpl.tab4': miss

[18:40:21.963] [bmv2] [D] [thread 23828] [934.0] [cxt 0] Action entry is NoAction - 

[18:40:21.963] [bmv2] [D] [thread 23828] [934.0] [cxt 0] Looking up key:

* hdr.ipv6.src_addr   : fe80000000000000645d6dfffe419006

[18:40:21.963] [bmv2] [D] [thread 23828] [934.0] [cxt 0] Table 'IngressPipeImpl.ndp_reply_table': miss

[18:40:21.963] [bmv2] [D] [thread 23828] [934.0] [cxt 0] Action entry is NoAction - 

[18:40:21.963] [bmv2] [D] [thread 23828] [934.0] [cxt 0] Looking up key:

The problem is, I can not see the relevant ip address of the hosts. It is important for my p4 program, because my p4 program only accepts packets from known IPv6 address. I have checked the relevant flowrules in the tables. But they are ok.

I can not understand why the switch do not get the source ipv6 addresses correctly. Do I need to configure something in mininet? 

Or any other tips to debug? Any kind of help or hint is welcome as I am really stuck in this issue for few days. 

[Debobroto Das]

the previous log seems not appropriate. Here is another log 

[18:47:43.298] [bmv2] [D] [thread 23780] [1062.2] [cxt 0] Transmitting packet of size 124 out of port 255

[18:47:43.298] [bmv2] [D] [thread 23774] [1063.0] [cxt 0] Table 'tbl_act': miss

[18:47:43.298] [bmv2] [D] [thread 23780] Transmitting packet-in

[18:47:43.298] [bmv2] [D] [thread 23774] [1063.0] [cxt 0] Action entry is act - 

[18:47:43.298] [bmv2] [D] [thread 23774] [1063.0] [cxt 0] Looking up key:

* hdr.ethernet.src_addr: 02eb02827a29

[18:47:43.298] [bmv2] [D] [thread 23774] [1063.0] [cxt 0] Table 'IngressPipeImpl.tab1': miss

[18:47:43.298] [bmv2] [D] [thread 23774] [1063.0] [cxt 0] Action entry is NoAction - 

[18:47:43.298] [bmv2] [D] [thread 23774] [1063.0] [cxt 0] Looking up key:

* hdr.ethernet.dst_addr: 0180c200000e

[18:47:43.298] [bmv2] [D] [thread 23774] [1063.0] [cxt 0] Table 'IngressPipeImpl.tab2': miss

[18:47:43.298] [bmv2] [D] [thread 23774] [1063.0] [cxt 0] Action entry is NoAction - 

[18:47:43.298] [bmv2] [D] [thread 23774] [1063.0] [cxt 0] Looking up key:

* hdr.ipv6.src_addr   : 00000000000000000000000000000000

[18:47:43.298] [bmv2] [D] [thread 23774] [1063.0] [cxt 0] Table 'IngressPipeImpl.tab3': miss

[18:47:43.298] [bmv2] [D] [thread 23774] [1063.0] [cxt 0] Action entry is NoAction - 

[18:47:43.298] [bmv2] [D] [thread 23774] [1063.0] [cxt 0] Looking up key:

* hdr.ipv6.dst_addr   : 00000000000000000000000000000000

[18:47:43.298] [bmv2] [D] [thread 23774] [1063.0] [cxt 0] Table 'IngressPipeImpl.tab4': miss

[18:47:43.298] [bmv2] [D] [thread 23774] [1063.0] [cxt 0] Action entry is NoAction - 

[18:47:43.298] [bmv2] [D] [thread 23774] [1063.0] [cxt 0] Looking up key:

* hdr.ipv6.src_addr   : 00000000000000000000000000000000

Here seems the packets are even not identified as IPv6 packets. For being sure, I have tried to check "hdr.ipv6.valid()" that also not works.  To me it seems like some how the bmv2 switch is not interpreting the packet as valid ipv6 packet