Results 1 to 5 of 5

Thread: Can't SSH or ping to local wireless until arp -s

  1. #1
    Join Date
    Jan 2012
    Beans
    3

    Can't SSH or ping to local wireless until arp -s

    When I first boot my laptop with a wireless connection, it is not accessible to other local computers using ssh or ping.

    However, if the same laptop boots with an ethernet connection, ssh and ping work correctly.

    In both cases, the laptop can access the WAN.

    I can only access the wireless laptop if I issue an arp command:

    arp -s 192.168.1.5 AA:BB:CC:dd:EE:FF

    After that, ssh and ping work as expected.

    What could be preventing the wireless interface from broadcasting its MAC address?
    Last edited by ckrosco; February 27th, 2013 at 06:27 PM. Reason: remove smiley

  2. #2
    Join Date
    Feb 2009
    Location
    Dallas, TX
    Beans
    7,640
    Distro
    Ubuntu 16.04 Xenial Xerus

    Re: Can't SSH or ping to local wireless until arp -s

    Hi ckrosco. Welcome to the forums

    My first guess would be to check your router:
    • Are the wired network and wireless network in the same IP range?
    • Does the laptop has set an static IP or a DHCP reservation using its ethernet MAC?

    Then, from the other computers:
    • Does the laptop appear with another MAC on the arp table (arp -v), or it does not appear at all?


    Regards.

  3. #3
    Join Date
    Jan 2012
    Beans
    3

    Re: Can't SSH or ping to local wireless until arp -s

    Quote Originally Posted by papibe View Post
    Are the wired network and wireless network in the same IP range?
    Yes, all devices are within 192.168.1.1 - 192.168.1.10
    Does the laptop has set an static IP or a DHCP reservation using its ethernet MAC?
    Laptop has a static IP - 192.168.1.5. I use the same IP address for both the wired and wireless laptop connection, which automatically switches depending on whether there's a cable attached.
    Does the laptop appear with another MAC on the arp table (arp -v), or it does not appear at all?
    The laptop does not appear in the arp table until I do a PING (which does not respond), then I see:

    Code:
    arp -v
    Address                  HWtype  HWaddress           Flags Mask            Iface
    laptop                           (incomplete)                              eth0
    Here is the ifconfig from the laptop:

    Code:
    ifconfig
    eth0      Link encap:Ethernet  HWaddr xx:xx:xx:xx:xx:xx  
              UP BROADCAST MULTICAST  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:42 Base address:0xc000 
    
    eth1      Link encap:Ethernet  HWaddr xx:xx:xx:xx:xx:xx  
              inet addr:192.168.1.5  Bcast:192.168.1.255  Mask:255.255.255.0
              inet6 addr: fe80::226:82ff:fe94:4817/64 Scope:Link
              UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
              RX packets:1161632 errors:116 dropped:0 overruns:0 frame:522662
              TX packets:795356 errors:77 dropped:0 overruns:0 carrier:0
              collisions:0 txqueuelen:1000 
              RX bytes:1688142507 (1.6 GB)  TX bytes:65040986 (65.0 MB)
              Interrupt:17 
    
    lo        Link encap:Local Loopback  
              inet addr:127.0.0.1  Mask:255.0.0.0
              inet6 addr: ::1/128 Scope:Host
              UP LOOPBACK RUNNING  MTU:16436  Metric:1
              RX packets:432 errors:0 dropped:0 overruns:0 frame:0
              TX packets:432 errors:0 dropped:0 overruns:0 carrier:0
              collisions:0 txqueuelen:0 
              RX bytes:34553 (34.5 KB)  TX bytes:34553 (34.5 KB)
    I used the HWaddr from eth1 in my arp command

    arp -s 192.168.1.5 AA:BB:CC:dd:EE:FF

    to gain access to the laptop, but without that manual entry into the arp table, I can't connect to the laptop.

  4. #4
    Join Date
    Feb 2009
    Location
    Dallas, TX
    Beans
    7,640
    Distro
    Ubuntu 16.04 Xenial Xerus

    Re: Can't SSH or ping to local wireless until arp -s

    Thanks.

    Is that the static IP defined on the router or the laptop itself?
    Is your router your DHCP server?

    Regards.

  5. #5
    Join Date
    Jan 2012
    Beans
    3

    Re: Can't SSH or ping to local wireless until arp -s

    Quote Originally Posted by papibe View Post
    Is that the static IP defined on the router or the laptop itself?
    Is your router your DHCP server?
    Thanks for your speedy replies.

    I've turned DHCP off. The ADSL modem has a setting to reserve IP addresses, but I think it's not necessary. But I have the laptop IP address set there.

    I have a ADSL modem connected to a switch, which is connected to a wireless router as a WAP. Should the wireless router have a setting for the laptop IP address?

    I believe the definition for the laptop IP address comes from the laptop itself, using the network manager GUI.

    The laptop /etc/network/interface file has this:

    Code:
    auto lo
    iface lo inet loopback
    Although in trying to sort out this problem I also tried this:

    Code:
    auto eth1
     iface eth1 inet static 
    address 192.168.1.5 
    netmask 255.255.255.0 
    broadcast 192.168.1.255 
    gateway 192.168.1.1 
    dns-nameservers 8.8.8.8 192.168.1.1
    Which didn't improve things, so I deleted that section.
    Last edited by ckrosco; February 27th, 2013 at 11:08 PM. Reason: line breaks

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •