>>куда рыть?
>show interface
>на предмет ошибок
>
>tcpdump
>чтобы понять что там конкретно происходит
FastEthernet0/0 is up, line protocol is up
Hardware is Fast Ethernet, address is 0009.7ca3.285a (bia 0009.7ca3.285a)
Internet address is 19X.XX.XX.X8/30
MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full-duplex, 100Mb/s, 100BaseTX/FX
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:00, output 00:00:00, output hang never
Last clearing of "show interface" counters never
Input queue: 0/4096/0/0 (size/max/drops/flushes); Total output drops: 15689
Queueing strategy: weighted fair
Output queue: 0/1000/64/15689 (size/max total/threshold/drops)
Conversations 0/31/256 (active/max active/max total)
Reserved Conversations 0/0 (allocated/max allocated)
Available Bandwidth 74936 kilobits/sec
5 minute input rate 472000 bits/sec, 665 packets/sec
5 minute output rate 317000 bits/sec, 387 packets/sec
240679228 packets input, 2840381181 bytes
Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog
0 input packets with dribble condition detected
155131479 packets output, 3215307443 bytes, 0 underruns(0/0/0)
0 output errors, 0 collisions, 1 interface resets
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier
0 output buffer failures, 0 output buffers swapped out
tcpdump есть возможность запустить только на тачке с которой собственно в телнет и ломлюсь:
root@xx:~# tcpdump -s 0 -ni rl1 host yy.98.54.78 and port 23
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on rl1, link-type EN10MB (Ethernet), capture size 65535 bytes
10:52:27.044423 IP xxx.92.136.130.54931 > yyy.98.54.78.23: P 1878076310:1878076312(2) ack 2638156895 win 65535
10:52:27.050516 IP yy.98.54.78.23 > xx.92.136.130.54931: P 1:3(2) ack 2 win 3992
10:52:27.053411 IP yy.98.54.78.23 > xx.92.136.130.54931: . 3:539(536) ack 2 win 3992
10:52:27.053482 IP xx.92.136.130.54931 > yy.98.54.78.23: . ack 539 win 65392
10:52:27.056675 IP yy.98.54.78.23 > xx.92.136.130.54931: . 539:1075(536) ack 2 win 3992
10:52:27.156639 IP xx.92.136.130.54931 > yy.98.54.78.23: . ack 1075 win 65535
10:52:34.482003 IP xx.92.136.130.54931 > yy.98.54.78.23: P 2:3(1) ack 1075 win 65535
10:52:34.684570 IP yy.98.54.78.23 > xx.92.136.130.54931: . ack 3 win 3991
10:52:36.526036 IP xx.92.136.130.54931 > yy.98.54.78.23: F 3:3(0) ack 1075 win 65535
10:52:36.531720 IP yy.98.54.78.23 > xx.92.136.130.54931: . ack 4 win 3991
10:52:36.629539 IP yy.98.54.78.23 > xx.92.136.130.54931: FP 1795:1795(0) ack 4 win 3991
10:52:36.629628 IP xx.92.136.130.54931 > yy.98.54.78.23: . ack 1075 win 65535
xx.92.136.130 - ип машины с которой ломлюсь
yy.98.54.78 - кошка