Einbahnstraße: kein echo reply nach request

[geloescht_vividos]

Hallo Zusammen,

habe ein wirklich fieses Problem auf der Arbeit, welches ich euch gerne erläutern würde, da ich hoffe, das jemand von Euch dazu etwas vielleicht einfällt.

Folgendes Problem: Auf ein echo request (gesendet von Server1) an eine IP eines Server2, erfolgt keine echo reply, obwohl der request im System eintrifft.

Dies Verhalten besteht auch bei geleerten ip-table-chains (shorewall clean).

Ping lokal auf den virtuellen Interfaces auf Server2 funktioniert erwartungsgemäß.

Ein cat /proc/sys/net/ipv*/icmp_echo_ignore_all auf Server2 ergibt 0.

Danke im Voraus für eure Mühe und die besten Grüße

Vividos

Folgend ein paar Auszüge von Konfigurationsdateien und Logs:

// interfaces server2

root@server2:~# cat /etc/network/interfaces

# This file describes the network interfaces available on your system

# and how to activate them. For more information, see interfaces(5).

# The loopback network interface

auto lo

iface lo inet loopback

# The primary network interface

auto eth0

iface eth0 inet static

address xx.xx.164.82

netmask 255.255.255.240

network xx.xx.164.80

broadcast xx.xx.164.95

gateway xx.xx.164.81

dns-search domain.tld

auto eth0:0

iface eth0:0 inet static

address xx.xx.164.83

netmask 255.255.255.240

network xx.xx.164.80

broadcast xx.xx.164.95

auto eth0:1

iface eth0:1 inet static

address xx.xx.164.84

netmask 255.255.255.240

network xx.xx.164.80

broadcast xx.xx.164.95

#auto eth0:2

iface eth0:2 inet static

address xx.xx.164.85

netmask 255.255.255.240

network xx.xx.164.80

broadcast xx.xx.164.95

#auto eth0:3

iface eth0:3 inet static

address xx.xx.164.86

netmask 255.255.255.240

network xx.xx.164.80

broadcast xx.xx.164.95

#auto eth0:4

iface eth0:4 inet static

address xx.xx.164.87

netmask 255.255.255.240

network xx.xx.164.80

broadcast xx.xx.164.95

#auto eth0:5

iface eth0:5 inet static

address xx.xx.164.88

netmask 255.255.255.240

network xx.xx.164.80

broadcast xx.xx.164.95

#auto eth0:6

iface eth0:6 inet static

address xx.xx.164.89

netmask 255.255.255.240

network xx.xx.164.80

broadcast xx.xx.164.95

#auto eth0:7

iface eth0:7 inet static

address xx.xx.164.90

netmask 255.255.255.240

network xx.xx.164.80

broadcast xx.xx.164.95

auto eth0:8

iface eth0:8 inet static

address xx.xx.164.91

netmask 255.255.255.240

network xx.xx.164.80

broadcast xx.xx.164.95

auto eth0:9

iface eth0:9 inet static

address xx.xx.164.92

netmask 255.255.255.240

network xx.xx.164.80

broadcast xx.xx.164.95

auto eth0:10

iface eth0:10 inet static

address xx.xx.164.93

netmask 255.255.255.240

network xx.xx.164.80

broadcast xx.xx.164.95

auto eth0:11

iface eth0:11 inet static

address xx.xx.164.94

netmask 255.255.255.240

network xx.xx.164.80

broadcast xx.xx.164.95

// ifconfig von server2

root@server2:~# ifconfig

eth0 Protokoll:Ethernet Hardware Adresse 00:xx:xx:xx:xx:00

inet Adresse:xx.xx.164.82 Bcast:xx.xx.164.95 Maske:255.255.255.240

inet6 Adresse: fe80::xxxx:xxxx:xxxx:c00/64 Gültigkeitsbereich:Verbindung

UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1

RX packets:98353257 errors:0 dropped:0 overruns:0 frame:0

TX packets:6732426 errors:0 dropped:0 overruns:0 carrier:0

Kollisionen:0 Sendewarteschlangenlänge:1000

RX bytes:2816903543 (2.6 GiB) TX bytes:1027636319 (980.0 MiB)

Interrupt:22 Basisadresse:0x4c00

eth0:0 Protokoll:Ethernet Hardware Adresse 00:xx:xx:xx:xx:00

inet Adresse:xx.xx.164.83 Bcast:xx.xx.164.95 Maske:255.255.255.240

UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1

Interrupt:22 Basisadresse:0x4c00

eth0:1 Protokoll:Ethernet Hardware Adresse 00:xx:xx:xx:xx:00

inet Adresse:xx.xx.164.84 Bcast:xx.xx.164.95 Maske:255.255.255.240

UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1

Interrupt:22 Basisadresse:0x4c00

eth0:8 Protokoll:Ethernet Hardware Adresse 00:xx:xx:xx:xx:00

inet Adresse:xx.xx.164.91 Bcast:xx.xx.164.95 Maske:255.255.255.240

UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1

Interrupt:22 Basisadresse:0x4c00

eth0:9 Protokoll:Ethernet Hardware Adresse 00:xx:xx:xx:xx:00

inet Adresse:xx.xx.164.92 Bcast:xx.xx.164.95 Maske:255.255.255.240

UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1

Interrupt:22 Basisadresse:0x4c00

eth0:10 Protokoll:Ethernet Hardware Adresse 00:xx:xx:xx:xx:00

inet Adresse:xx.xx.164.93 Bcast:xx.xx.164.95 Maske:255.255.255.240

UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1

Interrupt:22 Basisadresse:0x4c00

eth0:11 Protokoll:Ethernet Hardware Adresse 00:xx:xx:xx:xx:00

inet Adresse:xx.xx.164.94 Bcast:xx.xx.164.95 Maske:255.255.255.240

UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1

Interrupt:22 Basisadresse:0x4c00

lo Protokoll:Lokale Schleife

inet Adresse:127.0.0.1 Maske:255.0.0.0

inet6 Adresse: ::1/128 Gültigkeitsbereich:Maschine

UP LOOPBACK RUNNING MTU:16436 Metric:1

RX packets:16415596 errors:0 dropped:0 overruns:0 frame:0

TX packets:16415596 errors:0 dropped:0 overruns:0 carrier:0

Kollisionen:0 Sendewarteschlangenlänge:0

RX bytes:3954625213 (3.6 GiB) TX bytes:3954625213 (3.6 GiB)

// route -n server2

root@server2:/etc/network# route -n

Kernel IP Routentabelle

Ziel Router Genmask Flags Metric Ref Use Iface

xx.xx.164.80 0.0.0.0 255.255.255.240 U 0 0 0 eth0

0.0.0.0 xx.xx.164.81 0.0.0.0 UG 0 0 0 eth0

// ping von Server1

[root@server1:~]$ for i in 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 ; do ping xx.xx.164.$i -w 1 ; done

PING xx.xx.164.81 (xx.xx.164.81) 56(84) bytes of data.

64 bytes from xx.xx.164.81: icmp_seq=1 ttl=252 time=10.0 ms

--- xx.xx.164.81 ping statistics ---

1 packets transmitted, 1 received, 0% packet loss, time 0ms

rtt min/avg/max/mdev = 10.038/10.038/10.038/0.000 ms

PING xx.xx.164.82 (xx.xx.164.82) 56(84) bytes of data.

64 bytes from xx.xx.164.82: icmp_seq=1 ttl=60 time=9.77 ms

--- xx.xx.164.82 ping statistics ---

1 packets transmitted, 1 received, 0% packet loss, time 0ms

rtt min/avg/max/mdev = 9.773/9.773/9.773/0.000 ms

PING xx.xx.164.83 (xx.xx.164.83) 56(84) bytes of data.

64 bytes from xx.xx.164.83: icmp_seq=1 ttl=60 time=9.72 ms

--- xx.xx.164.83 ping statistics ---

1 packets transmitted, 1 received, 0% packet loss, time 0ms

rtt min/avg/max/mdev = 9.729/9.729/9.729/0.000 ms

PING xx.xx.164.84 (xx.xx.164.84) 56(84) bytes of data.

--- xx.xx.164.84 ping statistics ---

1 packets transmitted, 0 received, 100% packet loss, time 0ms

PING xx.xx.164.85 (xx.xx.164.85) 56(84) bytes of data.

--- xx.xx.164.85 ping statistics ---

2 packets transmitted, 0 received, 100% packet loss, time 1000ms

PING xx.xx.164.86 (xx.xx.164.86) 56(84) bytes of data.

--- xx.xx.164.86 ping statistics ---

2 packets transmitted, 0 received, 100% packet loss, time 1000ms

PING xx.xx.164.87 (xx.xx.164.87) 56(84) bytes of data.

--- xx.xx.164.87 ping statistics ---

2 packets transmitted, 0 received, 100% packet loss, time 1000ms

PING xx.xx.164.88 (xx.xx.164.88) 56(84) bytes of data.

--- xx.xx.164.88 ping statistics ---

2 packets transmitted, 0 received, 100% packet loss, time 1000ms

PING xx.xx.164.89 (xx.xx.164.89) 56(84) bytes of data.

--- xx.xx.164.89 ping statistics ---

2 packets transmitted, 0 received, 100% packet loss, time 1000ms

PING xx.xx.164.90 (xx.xx.164.90) 56(84) bytes of data.

--- xx.xx.164.90 ping statistics ---

2 packets transmitted, 0 received, 100% packet loss, time 1000ms

PING xx.xx.164.91 (xx.xx.164.91) 56(84) bytes of data.

--- xx.xx.164.91 ping statistics --- [11:54]

2 packets transmitted, 0 received, 100% packet loss, time 1000ms

PING xx.xx.164.92 (xx.xx.164.92) 56(84) bytes of data.

--- xx.xx.164.92 ping statistics ---

2 packets transmitted, 0 received, 100% packet loss, time 1000ms

PING xx.xx.164.93 (xx.xx.164.93) 56(84) bytes of data.

--- xx.xx.164.93 ping statistics ---

2 packets transmitted, 0 received, 100% packet loss, time 1000ms

PING xx.xx.164.94 (xx.xx.164.94) 56(84) bytes of data.

--- xx.xx.164.94 ping statistics ---

2 packets transmitted, 0 received, 100% packet loss, time 1000ms

PING xx.xx.164.95 (xx.xx.164.95) 56(84) bytes of data.

--- xx.xx.164.95 ping statistics ---

2 packets transmitted, 0 received, 100% packet loss, time 1000ms

// tcpdump von Server2

root@server2:~# tcpdump -n -i eth0 | grep xx.xx.52.73

tcpdump: verbose output suppressed, use -v or -vv for full protocol decode

listening on eth0, link-type EN10MB (Ethernet), capture size 96 bytes

11:53:47.446792 IP xx.xx.52.73 > xx.xx.164.82: icmp 64: echo request seq 1

11:53:47.446826 IP xx.xx.164.82 > xx.xx.52.73: icmp 64: echo reply seq 1

11:53:48.450626 IP xx.xx.52.73 > xx.xx.164.83: icmp 64: echo request seq 1

11:53:48.450657 IP xx.xx.164.83 > xx.xx.52.73: icmp 64: echo reply seq 1

11:53:49.454626 IP xx.xx.52.73 > xx.xx.164.84: icmp 64: echo request seq 1

11:53:56.506412 IP xx.xx.52.73 > xx.xx.164.91: icmp 64: echo request seq 1

11:53:57.507129 IP xx.xx.52.73 > xx.xx.164.91: icmp 64: echo request seq 2

11:53:57.514440 IP xx.xx.52.73 > xx.xx.164.92: icmp 64: echo request seq 1

11:53:58.515070 IP xx.xx.52.73 > xx.xx.164.92: icmp 64: echo request seq 2

11:53:58.522185 IP xx.xx.52.73 > xx.xx.164.93: icmp 64: echo request seq 1

11:53:59.523003 IP xx.xx.52.73 > xx.xx.164.93: icmp 64: echo request seq 2

11:53:59.530211 IP xx.xx.52.73 > xx.xx.164.94: icmp 64: echo request seq 1

11:54:00.530997 IP xx.xx.52.73 > xx.xx.164.94: icmp 64: echo request seq 2

[dgr243]

routingproblem?

weil das reply wird laut deinem tcpdump ja verschickt..

die frage muss also sein, wo im weiteren netz dieses versackt.

da wir das weitere netz ja nicht kennen, können wir dazu aber leider nix sagen ..

[geloescht_vividos]

routingproblem?

weil das reply wird laut deinem tcpdump ja verschickt..

..

Hallo dgr243,

die zwei replys laut tcpdump, welche verschickt werde, kommen beim Server1 an. Nur die restlichen requests, welche ankommen, werden leider nicht beantwortet.

Also nach meinem aktuellen Verständnis, werden laut tcpdump keine Antworten erstellt und versendet.

Grüße