PtP not working

PtP not working

[Antonio Di Bacco]

Anyone could explain this?

Two linux systems connected:

System A     <=========> System B
                   eth0                    eth0

Each system ha the following config:

# routing enabled
net.ipv4.ip_forward=1

#ethernet with no address associated and NOARP set
eth0      Link encap:Ethernet  HWaddr 08:00:3E:26:24:65
          UP BROADCAST RUNNING NOARP MULTICAST  MTU:1500  Metric:1
          RX packets:1306 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1325 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:732864 (715.6 KiB)  TX bytes:61643 (60.1 KiB)
          Base address:0x3c00

# Routing table
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
10.10.10.10     *               255.255.255.255 UH    0      0        0 eth0


I'm on System A and try to ping 10.10.10.10 but no answer. Where is the 
problem?

Bye,
Antonio.

Re: PtP not working

[Martijn Lievaart]

Antonio Di Bacco wrote:

>Anyone could explain this?
>
>Two linux systems connected:
>
>System A     <=========> System B
>                   eth0                    eth0
>
>Each system ha the following config:
>
># routing enabled
>net.ipv4.ip_forward=1
>
>#ethernet with no address associated and NOARP set
>eth0      Link encap:Ethernet  HWaddr 08:00:3E:26:24:65
>          UP BROADCAST RUNNING NOARP MULTICAST  MTU:1500  Metric:1
>          RX packets:1306 errors:0 dropped:0 overruns:0 frame:0
>          TX packets:1325 errors:0 dropped:0 overruns:0 carrier:0
>          collisions:0 txqueuelen:1000
>          RX bytes:732864 (715.6 KiB)  TX bytes:61643 (60.1 KiB)
>          Base address:0x3c00
>
># Routing table
>Kernel IP routing table
>Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
>10.10.10.10     *               255.255.255.255 UH    0      0        0 eth0
>
>
>I'm on System A and try to ping 10.10.10.10 but no answer. Where is the 
>problem?
>  
>

Which system has 10.10.10.10? None. So how can any system answer? Even 
if there was a 10.10.10.10, you disabled the arp mechanism, so you can 
never find out where it is. Finaly, for the return packets exactly the 
same problem occurs.

If you want to make a point to point connection over ethernet:
- Either just configure a subnet there.
- Or:
  - Assign addresses to the interfaces (can be the same address as 
another interface on the same box)
  - Create static arp addresses for the other box
  - Create routes as above for the address of the other box

I think you will still have to enable arp for this to work, in which 
case you can skip the static arp entries.

HTH,
M4

Re: PtP not working

[Antonio Di Bacco]

My problem is that both boxes should have the same ip address on eth0. They 
cannot be different.

Thank you,
Antonio

On Sunday 21 May 2006 13:20, Martijn Lievaart wrote:
> Antonio Di Bacco wrote:
> >Anyone could explain this?
> >
> >Two linux systems connected:
> >
> >System A     <=========> System B
> >                   eth0                    eth0
> >
> >Each system ha the following config:
> >
> ># routing enabled
> >net.ipv4.ip_forward=1
> >
> >#ethernet with no address associated and NOARP set
> >eth0      Link encap:Ethernet  HWaddr 08:00:3E:26:24:65
> >          UP BROADCAST RUNNING NOARP MULTICAST  MTU:1500  Metric:1
> >          RX packets:1306 errors:0 dropped:0 overruns:0 frame:0
> >          TX packets:1325 errors:0 dropped:0 overruns:0 carrier:0
> >          collisions:0 txqueuelen:1000
> >          RX bytes:732864 (715.6 KiB)  TX bytes:61643 (60.1 KiB)
> >          Base address:0x3c00
> >
> ># Routing table
> >Kernel IP routing table
> >Destination     Gateway         Genmask         Flags Metric Ref    Use
> > Iface 10.10.10.10     *               255.255.255.255 UH    0      0     
> >   0 eth0
> >
> >
> >I'm on System A and try to ping 10.10.10.10 but no answer. Where is the
> >problem?
>
> Which system has 10.10.10.10? None. So how can any system answer? Even
> if there was a 10.10.10.10, you disabled the arp mechanism, so you can
> never find out where it is. Finaly, for the return packets exactly the
> same problem occurs.
>
> If you want to make a point to point connection over ethernet:
> - Either just configure a subnet there.
> - Or:
>   - Assign addresses to the interfaces (can be the same address as
> another interface on the same box)
>   - Create static arp addresses for the other box
>   - Create routes as above for the address of the other box
>
> I think you will still have to enable arp for this to work, in which
> case you can skip the static arp entries.
>
> HTH,
> M4

Re: PtP not working

[Antonio Di Bacco]

Anyway I can have the same MAC address for both boxes on eth0.

On Sunday 21 May 2006 13:20, Martijn Lievaart wrote:
> Antonio Di Bacco wrote:
> >Anyone could explain this?
> >
> >Two linux systems connected:
> >
> >System A     <=========> System B
> >                   eth0                    eth0
> >
> >Each system ha the following config:
> >
> ># routing enabled
> >net.ipv4.ip_forward=1
> >
> >#ethernet with no address associated and NOARP set
> >eth0      Link encap:Ethernet  HWaddr 08:00:3E:26:24:65
> >          UP BROADCAST RUNNING NOARP MULTICAST  MTU:1500  Metric:1
> >          RX packets:1306 errors:0 dropped:0 overruns:0 frame:0
> >          TX packets:1325 errors:0 dropped:0 overruns:0 carrier:0
> >          collisions:0 txqueuelen:1000
> >          RX bytes:732864 (715.6 KiB)  TX bytes:61643 (60.1 KiB)
> >          Base address:0x3c00
> >
> ># Routing table
> >Kernel IP routing table
> >Destination     Gateway         Genmask         Flags Metric Ref    Use
> > Iface 10.10.10.10     *               255.255.255.255 UH    0      0     
> >   0 eth0
> >
> >
> >I'm on System A and try to ping 10.10.10.10 but no answer. Where is the
> >problem?
>
> Which system has 10.10.10.10? None. So how can any system answer? Even
> if there was a 10.10.10.10, you disabled the arp mechanism, so you can
> never find out where it is. Finaly, for the return packets exactly the
> same problem occurs.
>
> If you want to make a point to point connection over ethernet:
> - Either just configure a subnet there.
> - Or:
>   - Assign addresses to the interfaces (can be the same address as
> another interface on the same box)
>   - Create static arp addresses for the other box
>   - Create routes as above for the address of the other box
>
> I think you will still have to enable arp for this to work, in which
> case you can skip the static arp entries.
>
> HTH,
> M4