I had an experience this week of installing a 5510 ASA with 8.4.3, also tried 8.4.4(1) with the strange effect that I randomly was losing contact with the internet.
The interface stayed up/up. no errors or what so ever on the interface. Reseat of the DSL wire no result. Reseat of the outside interface cable made it work again. And after some time lost connectivity again. It did not recover by itself so had to let someone do a reseat again and again and.... The outside was using DHCP client. A lease was given and an IP also. Nothing strange to find.
Talked to the provider which could see the DSL and the DHCP lease.
Finally I downgraded the firmware to 8.4.2 and the problem was solved.
output
interface Ethernet0/0
nameif outside
security-level 0
ip address dhcp setroute
xx# sh int ip bri
Interface IP-Address OK? Method Status Protocol
Ethernet0/0 90.145.xx.xxx YES DHCP up up
Ethernet0/1 192.168.0.251 YES CONFIG up up
xx# sh ip add e0/0 dhcp lease
Temp IP addr: xx for peer on Interface: outside
Temp sub net mask: 255.255.248.0
DHCP Lease server: xx, state: 3 Bound
DHCP transaction id: 0x6D49626
Lease: 86400 secs, Renewal: 43200 secs, Rebind: 75600 secs
Temp default-gateway addr: 90.145.16.1
Next timer fires after: 42496 seconds
Retry count: 0 Client-ID: cisco-0021.a02e.9631-outside-xx
Proxy: FALSE
Hostname: xx
xx# sh ip add e0/0 dhcp ser
x# sh ip add e0/0 dhcp server
DHCP server: ANY (255.255.255.255)
Leases: 0
Offers: 0 Requests: 0 Acks: 0 Naks: 0
Declines: 0 Releases: 0 Bad: 0
DHCP server: 90.145.29.88
Leases: 1
Offers: 1 Requests: 2 Acks: 2 Naks: 0
Declines: 0 Releases: 0 Bad: 0
DNS0: 90.145.32.32, DNS1: 90.145.32.33
Subnet: 255.255.248.0 DNS Domain: unet.nl
xx# sh arp
outside 90.145.16.1 0024.97a6.521c 2274
outside 90.145.xx.xx 0024.97a6.521c 3371
