More IP weirdness

[prpr]

How/why does this happen? It seems wrong to me to respond to an IP address on an interface that's not up/connected on one that is but for a different subnet.
It's not proxy ARP or reverse path filtering related.
I haven't (yet) checked what happens in similar circumstances on a non-HDR device (e.g. Ubuntu VM).

$ telnet 192.0.2.100
Trying 192.0.2.100...
Connected to 192.0.2.100.
Escape character is '^]'.

Humax HDR-Fox T2 (humax) 1.03.12/3.14

humax ~ # route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
192.168.32.0    *               255.255.255.240 U     0      0        0 wlan0
default         192.168.32.14   0.0.0.0         UG    0      0        0 wlan0
humax ~ # ifconfig 
lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:54 errors:0 dropped:0 overruns:0 frame:0
          TX packets:54 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:4388 (4.2 Kb)  TX bytes:4388 (4.2 Kb)

wlan0     Link encap:Ethernet  HWaddr 00:1F:1F:xx:xx:xx  
          inet addr:192.168.32.13  Bcast:192.168.32.15  Mask:255.255.255.240
          UP BROADCAST RUNNING MULTICAST DYNAMIC  MTU:1500  Metric:1
          RX packets:1858464 errors:0 dropped:0 overruns:0 frame:0
          TX packets:8082 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:444832128 (424.2 Mb)  TX bytes:2032449 (1.9 Mb)

humax ~ # arp
Address                  HWtype  HWaddress           Flags Mask            Iface
192.168.32.14            ether   xx:xx:xx:xx:xx:xx   C                     wlan0
humax ~ # netstat -tn
Active Internet connections (w/o servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State      
tcp        0    124 192.0.2.100:23          192.0.2.254:53734       ESTABLISHED 

humax ~ # ifconfig eth0
eth0      Link encap:Ethernet  HWaddr DC:D3:21:xx:xx:xx  
          inet addr:192.0.2.100  Bcast:192.0.2.255  Mask:255.255.255.0
          BROADCAST MULTICAST DYNAMIC  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)
          Interrupt:16

 

[Black Hole]

I guess it's some sort of bug – I mean, who would have tested for that?

 

[MikeSh]

I guess it's some sort of bug – I mean, who would have tested for that?

Quite. It's a domestic device so 99.9% of the installations it could just assume the first 'net' (eg 192) was all it needed to worry about - somewhere in this property ...