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  1. #1

    Exclamation Problems connecting to "fake" access point

    My router broke so I am trying to setup something temporarily to share internet connection from my main pc (internet comes from modem connected directly to ethernet card) to other devices via an ad hoc network, for that I have a wifi adapter that uses the zd1211rw driver (i also have the alfa rtl8187 but that adapter is not working at all on ubuntu 12.04).

    The problem that I am having is that I can't connect to the wifi AP I create, it just stays "acquiring network address" and never finish connecting.

    My main computer OS is Ubuntu 12.04, this is what I am doing. First I put the wifi adapter on monitor mode with:

    airmon-ng start wlan2
    This creates a mon0 interface, then I use:

    airbase-ng -e MyNetName -c 11 -v mon0
    From here I can already see the MyNetName network using my laptop (with windows), but if I try to connect it stays at "acquiring network address". The tutorials I followed continue with these commands:

    ifconfig at0 up
    ifconfig at0 netmask
    route add -net netmask gw
    iptables --flush
    iptables --table nat --flush
    iptables --delete-chain
    iptables --table nat --delete-chain
    iptables -P FORWARD ACCEPT
    iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
    echo > '/var/lib/dhcp/dhcpd.leases'
    Then I start the dhcp server with

    dhcpd -d -f -cf /etc/dhcp/dhcpd.conf at0
    The dhcpd.conf file looks like this:

    ddns-update-style interim; <- also tried ad-hoc instead of interim
    default-lease-time 600;
    max-lease-time 7200;
    subnet netmask {
      option subnet-mask;
      option broadcast-address;
      option routers;
      option domain-name-servers;
    The output looks like:
    Internet Systems Consortium DHCP Server 4.1-ESV-R4
    Copyright 2004-2011 Internet Systems Consortium.
    All rights reserved.
    For info, please visit xxxxxx
    Not searching LDAP since ldap-server, ldap-port and ldap-base-dn were not specified in the config file
    Wrote 0 leases to leases file.
    Listening on LPF/at0/00:02:72:69:28:c8/
    Sending on   LPF/at0/00:02:72:69:28:c8/
    Sending on   Socket/fallback/fallback-net
    Can't create PID file /var/run/ Permission denied.
    The last command:

    echo "1" > /proc/sys/net/ipv4/ip_forward
    The airbase-ng command output looks like this:

    11:34:03  Created tap interface at0
    11:34:03  Trying to set MTU on at0 to 1500
    11:34:03  Trying to set MTU on mon0 to 1800
    11:34:03  Access Point with BSSID 00:02:72:69:28:C8 started.
    11:34:10  Client 70:F3:95:B3:27:76 associated (unencrypted) to ESSID: "MyNetName"
    11:34:13  Client 70:F3:95:B3:27:76 reassociated (unencrypted) to ESSID: "MyNetName"
    11:34:17  Client 70:F3:95:B3:27:76 reassociated (unencrypted) to ESSID: "MyNetName"
    11:34:21  Client 70:F3:95:B3:27:76 reassociated (unencrypted) to ESSID: "MyNetName"
    So my problem is that I cannot get an internal ip on the laptop that is trying to connect, the windows wifi manager thing just stays at "acquiring network address", airbase reacts by showing more of those reassociated messages while the laptop tries to connect. Another problem is that after running iptables --flush the internet in the main PC stops working, but I want to deal with that once I am able to fully connect to MyNetName.

    Does anyone have an idea what am I doing wrong?
    Last edited by wok_; 04-26-2013 at 03:53 PM.

  2. #2
    hello and welcome!

    per this line:
    Can't create PID file /var/run/ Permission denied.
    i would ask: how is dhcp started? root should be able to create that pid file. see if it is running, e.g.:
    ps auxww|grep dhcpd
    i would disconnect the modem from the internet, disable the firewall, and get dhcp working b/t the two computers using a wired ethernet connection before going any further w/wireless ad-hoc stuff.

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