Cisco ASA 5520 and DHCP relay

[Eimantas Zdanevičius]

> On the client what is in /etc/resolv.conf? Is it getting created
> by the dhcp client? What dhcp client are you using? dhclient, or
> something else?
>   
I'm using dhclient. /etc/resolv.conf created by dhclient and contains 
only nameserver lines:
nameserver 10.0.0.1
nameserver 10.0.0.2

these dns servers works correctly for other clients
> What setings do you have in dhcpd.conf for domain name servers?
>   
Linux DHCP server configuration:

default-lease-time  1800;    # 1/2 hour
max-lease-time      3600;    # 1 hour
min-lease-time       900;    # 1/4 hour
one-lease-per-client true;
option arp-cache-timeout 3600;
option netbios-node-type 1;
ddns-update-style none;
ddns-updates off;
authoritative;
subnet 10.5.0.0 netmask 255.255.255.0 {
       option routers                  10.5.0.254;
       option subnet-mask              255.255.255.0;
       option domain-name-servers      10.0.0.1,10.0.0.2;
       host asus { fixed-address 10.5.0.20; hardware ethernet
00:18:f3:3e:bc:3e; }
}
> If neither of these is helpful, then using tcpdump or wireshark
> to look at the packets on the network may give some clues.
>   
For now i can't test with tcpdumpor wireshark , i wil do this later.