odpoved na paket z jine ip adresy nezli cilove

Dalibor Straka dast na panelnet.cz
Pondělí Květen 16 00:43:42 CEST 2011


Dobry den,

mam debian squeeze (stable) a toto mi dela virtualni stroj na xenu, taktez
squeeze:

# tcpdump udp -n
[  743.566500] device eth0 entered promiscuous mode
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 65535 bytes
00:35:39.659879 IP 84.42.128.175.36542 > 212.20.98.95.53: 21523+ MX? testinet.cz. (29)
00:35:39.660766 IP 212.20.98.94.53 > 84.42.128.175.36542: 21523*- 1/0/2 MX mail.testinet.cz. 10 (82)

Kdyz powerdns posadim primo na ip=212.20.98.95, stroj odpovida korektne z teto IP.

Nevite nekdo, jak spravne nastavit, aby stroj odpovidal ze stejne IP, na jakou
packet prisel?

Zkousel jsem i strace, ale nic zajimaveho v nem nevidim:

# strace -p 1554 -f
Process 1554 attached with 8 threads - interrupt to quit
[pid  1563] futex(0xbe38b0, FUTEX_WAIT_PRIVATE, 0, NULL <unfinished ...>
[pid  1560] recvfrom(5,  <unfinished ...>
[pid  1559] futex(0xbe38b0, FUTEX_WAIT_PRIVATE, 0, NULL <unfinished ...>
[pid  1558] futex(0xbe38b0, FUTEX_WAIT_PRIVATE, 0, NULL <unfinished ...>
[pid  1557] futex(0xbe38b0, FUTEX_WAIT_PRIVATE, 0, NULL <unfinished ...>
[pid  1556] select(7, [6], NULL, NULL, NULL <unfinished ...>
[pid  1555] read(0,  <unfinished ...>
[pid  1554] futex(0x7f55bf5f99d0, FUTEX_WAIT, 1560, NULL
 <unfinished ...>
[pid  1560] <... recvfrom resumed> "t\232\1\0\0\1\0\0\0\0\0\0\10testinet\2cz\0\0\17\0\1", 512, 0, {sa_family=AF_INET, sin_port=htons(44263), sin_addr=inet_addr("84.42.128.175")}, [16]) = 29
[pid  1560] gettimeofday({1305498589, 938789}, NULL) = 0
[pid  1560] gettimeofday({1305498589, 938944}, NULL) = 0
[pid  1560] sendto(5, "t\232\205\0\0\1\0\1\0\0\0\2\10testinet\2cz\0\0\17\0\1\300\f\0"..., 82, 0, {sa_family=AF_INET, sin_port=htons(44263), sin_addr=inet_addr("84.42.128.175")}, 16) = 82
[pid  1560] gettimeofday({1305498589, 939257}, NULL) = 0
[pid  1560] recvfrom(5, "t\232\1\0\0\1\0\0\0\0\0\0\10testinet\2cz\0\0\17\0\1", 512, 0, {sa_family=AF_INET, sin_port=htons(44263), sin_addr=inet_addr("84.42.128.175")}, [16]) = 29
[pid  1560] gettimeofday({1305498594, 940204}, NULL) = 0
[pid  1560] gettimeofday({1305498594, 940381}, NULL) = 0
[pid  1560] sendto(5, "t\232\205\0\0\1\0\1\0\0\0\2\10testinet\2cz\0\0\17\0\1\300\f\0"..., 82, 0, {sa_family=AF_INET, sin_port=htons(44263), sin_addr=inet_addr("84.42.128.175")}, 16) = 82
[pid  1560] gettimeofday({1305498594, 940681}, NULL) = 0
[pid  1560] recvfrom(5, ^C <unfinished ...>
Process 1554 detached
Process 1555 detached
Process 1556 detached
Process 1557 detached
Process 1558 detached
Process 1559 detached
Process 1560 detached
Process 1563 detached


Diky za rady,
-- Dalibor Straka



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