Router dropping internet connection

[WiseGuy35]

Hello all,

My cisco 3640 is connected to a DSL modem and is getting an IP address via DHCP. Ever since I got everything working it has been dropping the connection. That is, i'll come back a few hours later and none of the hosts can access the internet. It also dropped one time i was playing COD4.

If I shutdown the interface and bring it back up, the internet comes back.

interface FastEthernet0/0
ip address dhcp
ip nat outside
duplex auto
speed auto

FastEthernet0/0 is up, line protocol is up
Hardware is AmdFE, address is 0004.9a24.a941 (bia 0004.9a24.a941)
Internet address is XXXX XXXX
MTU 1500 bytes, BW 10000 Kbit, DLY 1000 usec,
reliability 255/255, txload 1/255, rxload 8/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Half-duplex, 10Mb/s, 100BaseTX/FX
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:01, output 00:00:00, output hang never
Last clearing of "show interface" counters never
Queueing strategy: fifo
Output queue 0/40, 0 drops; input queue 0/75, 0 drops
5 minute input rate 333000 bits/sec, 28 packets/sec
5 minute output rate 6000 bits/sec, 14 packets/sec
239786 packets input, 321906088 bytes
Received 14 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog
0 input packets with dribble condition detected
144144 packets output, 15205411 bytes, 0 underruns(95/238/0)
0 output errors, 333 collisions, 7 interface resets
0 babbles, 0 late collision, 1940 deferred
0 lost carrier, 0 no carrier
0 output buffer failures, 0 output buffers swapped out

Thank you for the help

 

[North323]

what is your dhcp lease time?

 

[WiseGuy35]

IDK..I get the address from my ISP

 

[North323]

that could be the problem, can you ask them?

 

[burtsbees]

Is the ip address that you get a public or private one? If it is private, why are you natting? If it is public, then check the settings in the modem (timeouts, etc.). The dhcp lease on mine (that it hands out to the router, not the dhcp the MODEM gets, which is what North is talking about!) is set by default to 10 minutes...

/

tim@tim-laptop ~ $ sudo apt-get install windows
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Couldn't find package windows...Thank Goodness!

 

[WiseGuy35]

The Modem has no DHCP settings. I got it about 10 years ago and ive kept it because it needs no user settings and doesnt interfere with other devices. I can telnet to it, but it has very limit config settings. It has a small command prompt that basically says Bridge mode half duplex then its mac address. It is a Speedstream 5260.

My router behind this modem gets a public dhcp address. The modem itself has no ip address except that of the telnet address. this is why i have NAT setup on the router.

 

[North323]

i would look at that speed stream...if its 10 years old, may need replacing,

333 collisions, 7 interface resets
from your fa0/0

 

[WiseGuy35]

Its running in half duplex 10mbps, so i figured that was causing the collisons. And the 7 interface resets are from me resetting the device to get my internet back.

 

[North323]

have you asked your ISP to test the line?

 

[burtsbees]

Your fa interface negotiated correctly...

Half-duplex, 10Mb/s, 100BaseTX/FX

Can you http to the modem? I am surprised that it has no dhcp settings. I have one of those, and it is set to 10 minutes by default!

Again---do you get a public or private IP???

/

tim@tim-laptop ~ $ sudo apt-get install windows
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Couldn't find package windows...Thank Goodness!

 

[WiseGuy35]

I cannot http to the modem. THe problem is'nt the modem. Ive never had this problem when the modem is connected to my 2003 server running RRAS. I must be missing something in the router. Again, my router is recieving a PUBLIC dhcp address from my ISP. The modem is simply a bridge.

Modem ----->3640(public IP)---->Network
These are the available commands when i telnet to the modem.
Command-> ?

----------------------------------------------------------------------------
Command Description
----------------------------------------------------------------------------
show Shows system information, status, IP configuration
set Sets configuration parameters
delete Deletes NAPT server entries, routes, or PVCs
default Sets various parameters to factory defaults
clear Clears statistics
reboot Reboots the router
firmware Downloads new firmware to the router
getconfig Set router configuration from a file
putconfig Save router configuration to a file
quit (exit, logout, logoff) exits command session
logout (exit, logout, logoff) exits command session
logoff (exit, logout, logoff) exits command session
exit (exit, logout, logoff) exits command session
atmping Tests the ATM link by transmitting an OAM loopback cell
ping Sends datagram round-trip to specified IP host
traceroute Traces the route (hops) from the router to an IP address
Command->

These are the only user config commands....

Command-> show cfg
--- User Configuration
System Mode - Bridge
set ethcfg:
Ethernet Auto Negotiation Mode - Half
set ethip:
Ethernet IP Address/Netmask - 10.0.0.1/255.0.0.0
set ipgateway:
IP Gateway - 0.0.0.0
set snmpcfg:
SNMP Community - public
SNMP sysName -
SNMP sysLocation -
SNMP sysContact -
SNMP Trap Manager -
SNMP Trap Manager -
set tracecfg:
Trace Modules - TM_ERROR TM_WARN TM_INFO
set vc:
Bridge VC Configuration (Port/VPI/VCI/Rate) - 2/8/35/max
set bridgemac:
Bridge MAC Address - ff:ff:ff:ff:ff:ff
Bridge MAC Address - 01:80:c2:00:00:00
Bridge MAC Address - 01:80:c2:00:00:10
-- Press any key to continue --
set bridgefilter:
Bridge Filter Mode - disabled
set spantree:
Bridge Spanning Tree Configuration - disabled
set dnsresolver:
DNS Primary Server -
set hostname:
Host Name - SpeedStream
set domainname:
Domain Name - domain.invalid
Command->

 

[North323]

post the config of the 3460

 

[burtsbees]

Post a sh ip route as well as a scrubbed config. Otherwise, without the necessary info, we (or at least, I) cannot help.

/

tim@tim-laptop ~ $ sudo apt-get install windows
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Couldn't find package windows...Thank Goodness!

 

[WiseGuy35]

np, here is the show ip a ru config
Cisco3640#show ip route
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area
* - candidate default, U - per-user static route, o - ODR
P - periodic downloaded static route

Gateway of last resort is 74.x.xxx.x to network 0.0.0.0

R 192.168.10.0/24 [120/1] via 10.1.1.2, 00:00:23, Serial0/0
10.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C 10.1.1.2/32 is directly connected, Serial0/0
C 10.1.1.0/24 is directly connected, Serial0/0
R 192.168.1.0/24 [120/1] via 10.1.1.2, 00:00:23, Serial0/0
R 192.168.2.0/24 [120/1] via 10.1.1.2, 00:00:23, Serial0/0
74.0.0.0/20 is subnetted, 1 subnets
C 74.x.xxx.x is directly connected, FastEthernet0/0
R 192.168.3.0/24 [120/1] via 10.1.1.2, 00:00:24, Serial0/0
S* 0.0.0.0/0 [254/0] via 74.x.xxx.x
Cisco3640#

version 12.1
no service single-slot-reload-enable
service timestamps debug uptime
service timestamps log uptime
service password-encryption
!
hostname Cisco3640
!
logging rate-limit console 10 except errors
enable secret
!
ip subnet-zero
!
!
no ip finger
ip domain-name Home.local
ip name-server 71.x.x.xxx
ip name-server 76.x.xxx.xxx
ip name-server 192.168.1.4
!
!
!
!
interface FastEthernet0/0
ip address dhcp
ip nat outside
duplex auto
speed auto
!
interface Serial0/0
ip address 10.1.1.1 255.255.255.0
ip nat inside
encapsulation ppp
service-module t1 clock source internal
service-module t1 timeslots 1-24
!
router rip
version 2
network 10.0.0.0
!
ip nat inside source list 7 interface FastEthernet0/0 overload
ip classless
no ip http server
!

access-list 7 permit any
!
line con 0
password
login
transport input none
line aux 0
line vty 0 4
password
login
!
ntp clock-period 17179947
ntp server 192.168.1.4
end

Cisco3640#

 

[North323]

so fa0/0 is providing the dhcp, where is it getting it from? a domain controller?
interface FastEthernet0/0
ip address dhcp
ip nat outside
duplex auto
speed auto

Where is the gateway of last resort or route in your configuruation?

 

[WiseGuy35]

F0/0 is a dhcp client not server, and if you look in the ip route table, the router is automatically setting a gateway to the internet ip address.

 

[burtsbees]

You need to set that manually---ip route 0.0.0.0 0.0.0.0 next-hop

Post the sh ip route when you lose connectivity...

/

tim@tim-laptop ~ $ sudo apt-get install windows
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Couldn't find package windows...Thank Goodness!

 

[trashbin18]

Maybe you could set the static default to an exit interface instead of the dhcp ip. ip route o.o.o.o o.o.o.o fa0/0

also go ahead and hard code the fast ethernet interface to duplex half instead of negotiate just as a safey safe? I know it negotiated fine