Dotaz: nebezici routovani

[Ondrej]

Zdarvim! Mam nasledujici problemek:
Mam ADSL pripojeni k netu a to pres switch posilam na 4 kompy. poridil jsem si notebook a chci jeden ten komp pouzit jako router pro notase. Mam v nem dve sitovky, vsechno vypada v poradku. Z jakyhokoliv kompu muzu po siti i na net, router v pohode pingne notebook. Jenomze notebook nemuze nikam a nic nepingne notebook. Nakres spojeni je tady.
Kdyz se pokusim z notebooku pingnou treba 10.0.0.100 (root@notebook# ping 10.0.0.100), tak se podle tcpdumpu stane tohle:
10.0.0.200 - ARP: Kde je 10.0.0.100? -> 10.0.0.50 -> 10.0.0.3 -> 10.0.0.0 -> ARP: 10.0.0.100 je na blablabla -> 10.0.0.3 a dal uz ten paket nejde.

Vypisy route, ifconfig a iptables:

Notebook:

root@notebook# route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
localnet        *               255.0.0.0       U     0      0        0 eth0
loopback        *               255.0.0.0       U     0      0        0 lo
default         10.0.0.50       0.0.0.0         UG    1      0        0 eth0

root@notebook# ifconfig
eth0      Link encap:Ethernet  HWaddr 00:30:4F:29:37:5E  
          inet addr:10.0.0.200  Bcast:10.255.255.255  Mask:255.0.0.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:130 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1549 errors:0 dropped:0 overruns:0 carrier:0
          collisions:13 txqueuelen:100 
          RX bytes:11780 (11.5 Kb)  TX bytes:96458 (94.1 Kb)
          Interrupt:11 Base address:0xb000 

Router

root@router# route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
10.0.0.200      *               255.255.255.255 UH    0      0        0 eth1
localnet        *               255.0.0.0       U     0      0        0 eth0
localnet        *               255.0.0.0       U     0      0        0 eth1
loopback        *               255.0.0.0       U     0      0        0 lo
default         speedtouch.hack 0.0.0.0         UG    1      0        0 eth0

root@router# ifconfig
eth0      Link encap:Ethernet  HWaddr 00:0D:88:4E:25:52  
          inet addr:10.0.0.3  Bcast:10.255.255.255  Mask:255.0.0.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:2576 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1519 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:100 
          RX bytes:2838679 (2.7 Mb)  TX bytes:99547 (97.2 Kb)
          Interrupt:12 Base address:0xcc00 

eth1      Link encap:Ethernet  HWaddr 00:10:5A:30:5F:04  
          inet addr:10.0.0.50  Bcast:10.255.255.255  Mask:255.0.0.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:1541 errors:0 dropped:0 overruns:0 frame:0
          TX packets:118 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:100 
          RX bytes:96146 (93.8 Kb)  TX bytes:10956 (10.6 Kb)
          Interrupt:11 Base address:0xc000 

root@router# iptables -t nat -L
Chain PREROUTING (policy ACCEPT)
target     prot opt source               destination         

Chain POSTROUTING (policy ACCEPT)
target     prot opt source               destination         
MASQUERADE  all  --  anywhere             anywhere           

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination         

Server

root@server# route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
localnet        *               255.0.0.0       U     0      0        0 eth0
loopback        *               255.0.0.0       U     0      0        0 lo
default         speedtouch.hack 0.0.0.0         UG    1      0        0 eth0

root@server# ifconfig
eth0      Link encap:Ethernet  HWaddr 00:C0:4F:7E:6F:26  
          inet addr:10.0.0.100  Bcast:10.255.255.255  Mask:255.0.0.0
          inet6 addr: fe80::2c0:4fff:fe7e:6f26/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:7344585 errors:0 dropped:0 overruns:0 frame:0
          TX packets:10379994 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:1409251403 (1343.9 Mb)  TX bytes:4185272519 (3991.3 Mb)
          Interrupt:12 Base address:0xdc00 

root@server# iptables -L
Chain INPUT (policy ACCEPT)
target     prot opt source               destination         
LOG        all  --  anywhere             anywhere            LOG level debug prefix `BANDWIDTH_IN:' 
ACCEPT     all  --  localnet/24          anywhere            
ACCEPT     tcp  --  anywhere             anywhere            tcp dpt:ftp 
ACCEPT     tcp  --  anywhere             anywhere            tcp dpt:domain 
ACCEPT     tcp  --  anywhere             anywhere            tcp dpt:http 
ACCEPT     tcp  --  anywhere             anywhere            tcp dpt:https 
ACCEPT     tcp  --  anywhere             anywhere            tcp dpt:8000 
REJECT     tcp  --  anywhere             anywhere            tcp dpt:auth reject-with icmp-host-unreachable 
REJECT     tcp  -- !localnet/24          anywhere            tcp multiport dports netbios-ns,netbios-dgm,netbios-ssn,microsoft-ds reject-with icmp-net-unreachable 

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination         
LOG        all  --  anywhere             anywhere            LOG level debug prefix `BANDWIDTH_OUT:' 
LOG        all  --  anywhere             anywhere            LOG level debug prefix `BANDWIDTH_IN:' 

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination         
LOG        all  --  anywhere             anywhere            LOG level debug prefix `BANDWIDTH_OUT:'

Vsechny politiky jsou nastaveny na ACCEPT. Predem dik za jakoukoliv odpoved

Odpovědi

[Michal Kubeček]

Zkuste místo route použít 'ip route' nebo aspoň 'route -n', těžko hádat, co je u vás localnet (asi 10.0.0.0/24, ale kdo ví). Problém bude ale asi nejspíš v tom, že používáte na dvou segmentech stejný rozsah adres. To je sice v zásadě možné, ale začátečníkovi bych to rozhodně nedoporučil, protože ukonfigurovat to není úplně triviální.

[Ondrej]

Diky. Nastavil jsem na notebooku IPcko 172.16.1.200 a na routeru na eth1 172.16.1.1 a uz to slape jako hodinky