ACK Duplicate

Question

We have two servers which are used for data replication between them.

Issues

1.During replication the connectivity is getting down/slow regularly and packet is getting lost.Please find the below logs for your kind![alt text][1] reference.

8954069.0: ethernet0/1(i) len=70:002451aefc00->00239c82b805/8100/0800, tag 635
              10.1.1.1 -> 192.1.1.1/6
              vhl=45, tos=00, id=47907, frag=4000, ttl=63 tlen=52
              tcp:ports 57105->10560, seq=2650136876, ack=314843383, flag=8010/ACK
              00 23 9c 82 b8 05 00 24 51 ae fc 00 81 00 02 7b     .#.....$Q......{
              08 00 45 00 00 34 bb 23 40 00 3f 06 98 ab 0a 0b     ..E..4.#@.?.....
              10 b6 c0 a8 0c 8c df 11 29 40 9d f5 e1 2c 12 c4     ........)@...,..
              20 f7 80 10 00 26 5e 24 00 00 01 01 08 0a 86 a9     .....&^$........
              57 7c 65 0d 32 1b                                   W|e.2.
8954069.0: ethernet0/2(o) len=66:00239c82b806->002283a4d989/0800
10.1.1.1 -> 192.1.1.1/6
vhl=45, tos=00, id=47907, frag=4000, ttl=62 tlen=52
tcp:ports 57105->10560, seq=2650136876, ack=314843383, flag=8010/ACK
00 22 83 a4 d9 89 00 23 9c 82 b8 06 08 00 45 00     ."…..#……E.
00 34 bb 23 40 00 3e 06 99 ab 0a 0b 10 b6 c0 a8     .4.#@.>………
0c 8c df 11 29 40 9d f5 e1 2c 12 c4 20 f7 80 10     ….)@…,……
00 26 5e 24 00 00 01 01 08 0a 86 a9 57 7c 65 0d     .&^$……..W|e.
32 1b                                               2.
8954069.0: ethernet0/2(i) len=66:002283a4d989->00239c82b806/0800
192.1.1.1 -> 10.1.1.1/6
vhl=45, tos=00, id=10758, frag=4000, ttl=61 tlen=52
tcp:ports 10560->57105, seq=314843383, ack=2650136877, flag=8010/ACK
00 23 9c 82 b8 06 00 22 83 a4 d9 89 08 00 45 00     .#….."……E.
00 34 2a 06 40 00 3d 06 2b c9 c0 a8 0c 8c 0a 0b     .4*[email protected]=.+…….
10 b6 29 40 df 11 12 c4 20 f7 9d f5 e1 2d 80 10     ..)@………-..
00 23 5d ed 00 00 01 01 08 0a 65 0f 06 f6 86 a7     .#]…….e…..
82 da                                               ..
8954069.0: ethernet0/1(o) len=70:00239c82b805->002451aefc00/8100/0800, tag 635
192.1.1.1 -> 10.1.1.1/6
vhl=45, tos=00, id=10758, frag=4000, ttl=60 tlen=52
tcp:ports 10560->57105, seq=314843383, ack=2650136877, flag=8010/ACK
00 24 51 ae fc 00 00 23 9c 82 b8 05 81 00 02 7b     .$Q….#…….{
08 00 45 00 00 34 2a 06 40 00 3c 06 2c c9 c0 a8     ..E..4*[email protected]<.,…
0c 8c 0a 0b 10 b6 29 40 df 11 12 c4 20 f7 9d f5     ……)@……..
e1 2d 80 10 00 23 5d ed 00 00 01 01 08 0a 65 0f     .-…#]…….e.
06 f6 86 a7 82 da                                   ……
8954069.0: ethernet0/2(i) len=66:002283a4d989->00239c82b806/0800
192.1.1.1 -> 10.1.1.1/6
vhl=45, tos=00, id=10759, frag=4000, ttl=61 tlen=52
tcp:ports 10560->57105, seq=314843382, ack=2650136877, flag=8010/ACK
00 23 9c 82 b8 06 00 22 83 a4 d9 89 08 00 45 00     .#….."……E.
00 34 2a 07 40 00 3d 06 2b c8 c0 a8 0c 8c 0a 0b     .4*[email protected]=.+…….
10 b6 29 40 df 11 12 c4 20 f6 9d f5 e1 2d 80 10     ..)@………-..
00 23 5d cf 00 00 01 01 08 0a 65 0f 07 15 86 a7     .#]…….e…..
82 da                                               ..
8954069.0: ethernet0/1(o) len=70:00239c82b805->002451aefc00/8100/0800, tag 635
192.1.1.1 -> 10.1.1.1/6
vhl=45, tos=00, id=10759, frag=4000, ttl=60 tlen=52
tcp:ports 10560->57105, seq=314843382, ack=2650136877, flag=8010/ACK
00 24 51 ae fc 00 00 23 9c 82 b8 05 81 00 02 7b     .$Q….#…….{
08 00 45 00 00 34 2a 07 40 00 3c 06 2c c8 c0 a8     ..E..4*[email protected]<.,…
0c 8c 0a 0b 10 b6 29 40 df 11 12 c4 20 f6 9d f5     ……)@……..
e1 2d 80 10 00 23 5d cf 00 00 01 01 08 0a 65 0f     .-…#]…….e.
07 15 86 a7 82 da                                   ……
8954069.0: ethernet0/1(i) len=70:002451aefc00->00239c82b805/8100/0800, tag 635
10.1.1.1 -> 192.1.1.1/6
vhl=45, tos=00, id=47908, frag=4000, ttl=63 tlen=52
tcp:ports 57105->10560, seq=2650136877, ack=314843383, flag=8010/ACK
00 23 9c 82 b8 05 00 24 51 ae fc 00 81 00 02 7b     .#…..$Q……{
08 00 45 00 00 34 bb 24 40 00 3f 06 98 aa 0a 0b     [email protected]?…..
10 b6 c0 a8 0c 8c df 11 29 40 9d f5 e1 2d 12 c4     ……..)@…-..
20 f7 80 10 00 26 89 0c 00 00 01 01 08 0a 86 a9     …..&……….
57 b6 65 0f 06 f6                                   W.e…
8954069.0: ethernet0/2(o) len=66:00239c82b806->002283a4d989/0800
10.1.1.1 -> 192.1.1.1/6
vhl=45, tos=00, id=47908, frag=4000, ttl=62 tlen=52
tcp:ports 57105->10560, seq=2650136877, ack=314843383, flag=8010/ACK
00 22 83 a4 d9 89 00 23 9c 82 b8 06 08 00 45 00     ."…..#……E.
00 34 bb 24 40 00 3e 06 99 aa 0a 0b 10 b6 c0 a8     [email protected]>………
0c 8c df 11 29 40 9d f5 e1 2d 12 c4 20 f7 80 10     ….)@…-……
00 26 89 0c 00 00 01 01 08 0a 86 a9 57 b6 65 0f     .&……….W.e.
06 f6                                               ..
8954085.0: ethernet0/1(i) len=70:002451aefc00->00239c82b805/8100/0800, tag 635
10.1.1.1 -> 192.1.1.1/6
vhl=45, tos=00, id=38820, frag=4000, ttl=63 tlen=52
tcp:ports 59983->10560, seq=3297725813, ack=966268089, flag=8010/ACK
00 23 9c 82 b8 05 00 24 51 ae fc 00 81 00 02 7b     .#…..$Q……{
08 00 45 00 00 34 97 a4 40 00 3f 06 bc 2a 0a 0b     [email protected]?..*..
10 b6 c0 a8 0c 8c ea 4f 29 40 c4 8f 4d 75 39 98     …….O)@..Mu9.
14 b9 80 10 00 26 25 c2 00 00 01 01 08 0a 86 a9     …..&%………
97 36 65 0d 72 0c                                   .6e.r.
8954085.0: ethernet0/2(o) len=66:00239c82b806->002283a4d989/0800
10.1.1.1 -> 192.1.1.1/6
vhl=45, tos=00, id=38820, frag=4000, ttl=62 tlen=52
tcp:ports 59983->10560, seq=3297725813, ack=966268089, flag=8010/ACK
00 22 83 a4 d9 89 00 23 9c 82 b8 06 08 00 45 00     ."…..#……E.
00 34 97 a4 40 00 3e 06 bd 2a 0a 0b 10 b6 c0 a8     [email protected]>..*……
0c 8c ea 4f 29 40 c4 8f 4d 75 39 98 14 b9 80 10     …O)@..Mu9…..
00 26 25 c2 00 00 01 01 08 0a 86 a9 97 36 65 0d     .&%……….6e.
72 0c                                               r.
8954085.0: ethernet0/2(i) len=66:002283a4d989->00239c82b806/0800
192.1.1.1 -> 10.1.1.1/6
vhl=45, tos=00, id=31902, frag=4000, ttl=61 tlen=52
tcp:ports 10560->59983, seq=966268089, ack=3297725814, flag=8010/ACK
00 23 9c 82 b8 06 00 22 83 a4 d9 89 08 00 45 00     .#….."……E.
00 34 7c 9e 40 00 3d 06 d9 30 c0 a8 0c 8c 0a 0b     .4|[email protected]=..0……
10 b6 29 40 ea 4f 39 98 14 b9 c4 8f 4d 76 80 10     ..)@.O9…..Mv..
00 47 25 86 00 00 01 01 08 0a 65 0f 46 b0 86 a7     .G%…….e.F…
c2 ac                                               ..
8954085.0: ethernet0/1(o) len=70:00239c82b805->002451aefc00/8100/0800, tag 635
192.1.1.1 -> 10.1.1.1/6
vhl=45, tos=00, id=31902, frag=4000, ttl=60 tlen=52
tcp:ports 10560->59983, seq=966268089, ack=3297725814, flag=8010/ACK
00 24 51 ae fc 00 00 23 9c 82 b8 05 81 00 02 7b     .$Q….#…….{
08 00 45 00 00 34 7c 9e 40 00 3c 06 da 30 c0 a8     ..E..4|[email protected]<..0..
0c 8c 0a 0b 10 b6 29 40 ea 4f 39 98 14 b9 c4 8f     ……)@.O9…..
4d 76 80 10 00 47 25 86 00 00 01 01 08 0a 65 0f     Mv…G%…….e.
46 b0 86 a7 c2 ac                                   F…..
8954085.0: ethernet0/2(i) len=66:002283a4d989->00239c82b806/0800
192.1.1.1 -> 10.1.1.1/6
vhl=45, tos=00, id=31903, frag=4000, ttl=61 tlen=52
tcp:ports 10560->59983, seq=966268088, ack=3297725814, flag=8010/ACK
00 23 9c 82 b8 06 00 22 83 a4 d9 89 08 00 45 00     .#….."……E.
00 34 7c 9f 40 00 3d 06 d9 2f c0 a8 0c 8c 0a 0b     .4|[email protected]=../……
10 b6 29 40 ea 4f 39 98 14 b8 c4 8f 4d 76 80 10     ..)@.O9…..Mv..
00 47 25 50 00 00 01 01 08 0a 65 0f 46 e7 86 a7     .G%P……e.F…
c2 ac                                               ..
8954085.0: ethernet0/1(o) len=70:00239c82b805->002451aefc00/8100/0800, tag 635
192.1.1.1 -> 10.1.1.1/6
vhl=45, tos=00, id=31903, frag=4000, ttl=60 tlen=52
tcp:ports 10560->59983, seq=966268088, ack=3297725814, flag=8010/ACK
00 24 51 ae fc 00 00 23 9c 82 b8 05 81 00 02 7b     .$Q….#…….{
08 00 45 00 00 34 7c 9f 40 00 3c 06 da 2f c0 a8     ..E..4|[email protected]<../..
0c 8c 0a 0b 10 b6 29 40 ea 4f 39 98 14 b8 c4 8f     ……)@.O9…..
4d 76 80 10 00 47 25 50 00 00 01 01 08 0a 65 0f     Mv…G%P……e.
46 e7 86 a7 c2 ac                                   F…..
8954085.0: ethernet0/1(i) len=70:002451aefc00->00239c82b805/8100/0800, tag 635
10.1.1.1 -> 192.1.1.1/6
vhl=45, tos=00, id=38821, frag=4000, ttl=63 tlen=52
tcp:ports 59983->10560, seq=3297725814, ack=966268089, flag=8010/ACK
00 23 9c 82 b8 05 00 24 51 ae fc 00 81 00 02 7b     .#…..$Q……{
08 00 45 00 00 34 97 a5 40 00 3f 06 bc 29 0a 0b     [email protected]?..)..
10 b6 c0 a8 0c 8c ea 4f 29 40 c4 8f 4d 76 39 98     …….O)@..Mv9.
14 b9 80 10 00 26 50 c9 00 00 01 01 08 0a 86 a9     …..&P………
97 88 65 0f 46 b0                                   ..e.F.
8954085.0: ethernet0/2(o) len=66:00239c82b806->002283a4d989/0800
10.1.1.1 -> 192.1.1.1/6
vhl=45, tos=00, id=38821, frag=4000, ttl=62 tlen=52
tcp:ports 59983->10560, seq=3297725814, ack=966268089, flag=8010/ACK
00 22 83 a4 d9 89 00 23 9c 82 b8 06 08 00 45 00     ."…..#……E.
00 34 97 a5 40 00 3e 06 bd 29 0a 0b 10 b6 c0 a8     [email protected]>..)……
0c 8c ea 4f 29 40 c4 8f 4d 76 39 98 14 b9 80 10     …O)@..Mv9…..
00 26 50 c9 00 00 01 01 08 0a 86 a9 97 88 65 0f     .&P………..e.
46 b0                                               F.

Answer 1

Are the servers linux? If so look to iptables to help troubleshoot. Here is a good article to log the dropped packets:

http://www.thegeekstuff.com/2012/08/iptables-log-packets/

I have also in the past had issues with slow/drooped connections when one device is implementing 802.1Q VLAN tagging and the other is not but seeing that you are going from private class A to class C subnet I would think it may be with the masking either on one of the servers or a router inbetween.