dd-wrt and multiple subnets

Michael Tinsay <tinsami1-/[email protected]>
Newsgroups gmane.org.user-groups.linux.philippine
Message-ID <[email protected]>
Hello everyone.

I'm tinkering around with an ASUS RT-N16 router.  I have flashed the firmware with DD-WRT v24-sp2 (06/08/12) mega - build 19342.  Things are working fine for general use, but I seeing weird behavior in my more exotic setup here at the office.

You see, I have 4 subnets in the office all accessible from anywhere in the LAN:'

     subnet 1 (192.168.100.0/24) for a few servers and specialized users.  This is also my legacy subnet -- the original subnet of the office lan.
     subnet 2 (10.10.10.0/21) is the new office lan subnet, for the general use of the population and where most of the servers are.
     subnet 3 (192.168.200.0/24) is the subnet for the network printers (users print via a printserver visible in subnet 2) and a few kiosks.
     subnet 4 (10.20.30.0/24) is a sandbox subnet (where the fun stuff happens)

The router is connected to the office lan via the WAN port.  I configured the router to be on subnet 1 and added the other subnets via the Startup commands in DD-WRT's web-based admin.

Here's the result of ifconfig:

br0       Link encap:Ethernet  HWaddr 10:BF:48:E7:24:65  
          inet addr:192.168.1.1  Bcast:192.168.1.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:81590 errors:0 dropped:0 overruns:0 frame:0
          TX packets:45139 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:9140521 (8.7 MiB)  TX bytes:30687125 (29.2 MiB)
br0:0     Link encap:Ethernet  HWaddr 10:BF:48:E7:24:65  
          inet addr:169.254.255.1  Bcast:169.254.255.255  Mask:255.255.0.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
eth0      Link encap:Ethernet  HWaddr 10:BF:48:E7:24:65  
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:156473 errors:18 dropped:0 overruns:0 frame:9
          TX packets:24758 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:51222413 (48.8 MiB)  TX bytes:7835838 (7.4 MiB)
          Interrupt:4 Base address:0x2000 
eth1      Link encap:Ethernet  HWaddr 10:BF:48:E7:24:67  
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:32926 errors:0 dropped:0 overruns:0 frame:133764
          TX packets:43089 errors:7 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:3864980 (3.6 MiB)  TX bytes:28792724 (27.4 MiB)
          Interrupt:3 Base address:0x1000 
lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          UP LOOPBACK RUNNING MULTICAST  MTU:16436  Metric:1
          RX packets:16 errors:0 dropped:0 overruns:0 frame:0
          TX packets:16 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:1671 (1.6 KiB)  TX bytes:1671 (1.6 KiB)
vlan1     Link encap:Ethernet  HWaddr 10:BF:48:E7:24:65  
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:1951 errors:0 dropped:0 overruns:0 frame:0
          TX packets:11623 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:125148 (122.2 KiB)  TX bytes:6007973 (5.7 MiB)
vlan2     Link encap:Ethernet  HWaddr 10:BF:48:E7:24:66  
          inet addr:192.168.100.227  Bcast:192.168.100.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:154463 errors:0 dropped:0 overruns:0 frame:0
          TX packets:13135 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:48272967 (46.0 MiB)  TX bytes:1827865 (1.7 MiB)
vlan2:0   Link encap:Ethernet  HWaddr 10:BF:48:E7:24:66  
          inet addr:10.10.10.69  Bcast:10.10.17.255  Mask:255.255.248.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
vlan2:1   Link encap:Ethernet  HWaddr 10:BF:48:E7:24:66  
          inet addr:192.168.200.227  Bcast:192.168.200.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
vlan2:2   Link encap:Ethernet  HWaddr 10:BF:48:E7:24:66  
          inet addr:10.20.30.227  Bcast:10.20.30.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

And the route -n shows:

Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
10.20.30.0      0.0.0.0         255.255.255.0   U     0      0        0 vlan2
192.168.1.0     0.0.0.0         255.255.255.0   U     0      0        0 br0
192.168.200.0   0.0.0.0         255.255.255.0   U     0      0        0 vlan2
192.168.100.0   0.0.0.0         255.255.255.0   U     0      0        0 vlan2
10.10.10.0      0.0.0.0         255.255.248.0   U     0      0        0 vlan2
169.254.0.0     0.0.0.0         255.255.0.0     U     0      0        0 br0
127.0.0.0       0.0.0.0         255.0.0.0       U     0      0        0 lo
0.0.0.0         192.168.100.2   0.0.0.0         UG    0      0        0 vlan2

Here's the weird behavior I'm experiencing:

From my devices (a laptop connected via LAN cable with a static ip; another laptop, an iPad, and an android phone connected via WiFi with dynamic ip) behind the router, Internet browsing, SSH to servers, ping, and everything else works great on subnet 1 (192.168.100.0/24) -- no problem here.  I can print to a network printer directly via subnet 3 (192.168.200.0/24).  I can ping only a few of the servers in subnet 2 (10.10.10.0/21) and browsing a web server on subnet 2 doesn't work, neither does SSH.  The same is true for subnet 4.

From the router (via ssh) I can ping the machines in subnets 2 and 4.  I'm able to connect to servers in subnets 3 and 4 via ssh tunneling.

Anybody have any idea on what/where to look at?

Just in case, iptables -nxvL shows:

Chain INPUT (policy ACCEPT 0 packets, 0 bytes)
    pkts      bytes target     prot opt in     out     source               destination         
   34580 15774302 logaccept  0    --  *      *       0.0.0.0/0            0.0.0.0/0           state RELATED,ESTABLISHED 
       0        0 logdrop    udp  --  vlan2  *       0.0.0.0/0            0.0.0.0/0           udp dpt:520 
       0        0 logdrop    udp  --  br0    *       0.0.0.0/0            0.0.0.0/0           udp dpt:520 
       0        0 ACCEPT     udp  --  *      *       0.0.0.0/0            0.0.0.0/0           udp dpt:520 
    2294   137640 logaccept  tcp  --  *      *       0.0.0.0/0            192.168.1.1         tcp dpt:443 
       0        0 ACCEPT     icmp --  vlan2  *       0.0.0.0/0            0.0.0.0/0           
     435    13920 ACCEPT     2    --  *      *       0.0.0.0/0            0.0.0.0/0           
       0        0 ACCEPT     tcp  --  *      *       0.0.0.0/0            0.0.0.0/0           tcp dpt:113 
       2      109 ACCEPT     0    --  lo     *       0.0.0.0/0            0.0.0.0/0           state NEW 
       6     1438 logaccept  0    --  br0    *       0.0.0.0/0            0.0.0.0/0           state NEW 
   99070 21162373 logdrop    0    --  *      *       0.0.0.0/0            0.0.0.0/0           
Chain FORWARD (policy ACCEPT 0 packets, 0 bytes)
    pkts      bytes target     prot opt in     out     source               destination         
       0        0 logaccept  47   --  *      vlan2   192.168.1.0/24       0.0.0.0/0           
       0        0 logaccept  tcp  --  *      vlan2   192.168.1.0/24       0.0.0.0/0           tcp dpt:1723 
       0        0 logaccept  0    --  br0    br0     0.0.0.0/0            0.0.0.0/0           
     645    38180 TCPMSS     tcp  --  *      *       0.0.0.0/0            0.0.0.0/0           tcp flags:0x06/0x02 TCPMSS clamp to PMTU 
   36727 18426680 lan2wan    0    --  *      *       0.0.0.0/0            0.0.0.0/0           
   23540 13704724 logaccept  0    --  *      *       0.0.0.0/0            0.0.0.0/0           state RELATED,ESTABLISHED 
   12600  4684259 logaccept  udp  --  vlan2  *       0.0.0.0/0            224.0.0.0/4         
       0        0 logaccept  tcp  --  *      *       0.0.0.0/0            192.168.1.22        tcp dpt:22 
       0        0 logaccept  tcp  --  *      *       0.0.0.0/0            192.168.1.22        tcp dpt:22 
       0        0 TRIGGER    0    --  vlan2  br0     0.0.0.0/0            0.0.0.0/0           TRIGGER type:in match:0 relate:0 
     587    37697 trigger_out  0    --  br0    *       0.0.0.0/0            0.0.0.0/0           
     585    37605 logaccept  0    --  br0    *       0.0.0.0/0            0.0.0.0/0           state NEW 
       2       92 logdrop    0    --  *      *       0.0.0.0/0            0.0.0.0/0           
Chain OUTPUT (policy ACCEPT 29813 packets, 16957527 bytes)
    pkts      bytes target     prot opt in     out     source               destination         
Chain advgrp_1 (0 references)
    pkts      bytes target     prot opt in     out     source               destination         
Chain advgrp_10 (0 references)
    pkts      bytes target     prot opt in     out     source               destination         
Chain advgrp_2 (0 references)
    pkts      bytes target     prot opt in     out     source               destination         
Chain advgrp_3 (0 references)
    pkts      bytes target     prot opt in     out     source               destination         
Chain advgrp_4 (0 references)
    pkts      bytes target     prot opt in     out     source               destination         
Chain advgrp_5 (0 references)
    pkts      bytes target     prot opt in     out     source               destination         
Chain advgrp_6 (0 references)
    pkts      bytes target     prot opt in     out     source               destination         
Chain advgrp_7 (0 references)
    pkts      bytes target     prot opt in     out     source               destination         
Chain advgrp_8 (0 references)
    pkts      bytes target     prot opt in     out     source               destination         
Chain advgrp_9 (0 references)
    pkts      bytes target     prot opt in     out     source               destination         
Chain grp_1 (0 references)
    pkts      bytes target     prot opt in     out     source               destination         
Chain grp_10 (0 references)
    pkts      bytes target     prot opt in     out     source               destination         
Chain grp_2 (0 references)
    pkts      bytes target     prot opt in     out     source               destination         
Chain grp_3 (0 references)
    pkts      bytes target     prot opt in     out     source               destination         
Chain grp_4 (0 references)
    pkts      bytes target     prot opt in     out     source               destination         
Chain grp_5 (0 references)
    pkts      bytes target     prot opt in     out     source               destination         
Chain grp_6 (0 references)
    pkts      bytes target     prot opt in     out     source               destination         
Chain grp_7 (0 references)
    pkts      bytes target     prot opt in     out     source               destination         
Chain grp_8 (0 references)
    pkts      bytes target     prot opt in     out     source               destination         
Chain grp_9 (0 references)
    pkts      bytes target     prot opt in     out     source               destination         
Chain lan2wan (1 references)
    pkts      bytes target     prot opt in     out     source               destination         
Chain logaccept (11 references)
    pkts      bytes target     prot opt in     out     source               destination         
   73605 34339968 ACCEPT     0    --  *      *       0.0.0.0/0            0.0.0.0/0           
Chain logdrop (4 references)
    pkts      bytes target     prot opt in     out     source               destination         
   99072 21162465 DROP       0    --  *      *       0.0.0.0/0            0.0.0.0/0           
Chain logreject (0 references)
    pkts      bytes target     prot opt in     out     source               destination         
       0        0 REJECT     tcp  --  *      *       0.0.0.0/0            0.0.0.0/0           reject-with tcp-reset 
Chain trigger_out (1 references)
    pkts      bytes target     prot opt in     out     source               destination 


Any help is appreciated.


--- mike t.

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