Internet Connection cuts in half when 2811 connected

[R3AP3R]

Setup is a cable modem going into a 2811 doing dhcp / NAT serving 4 pcs.

When pc plugged directly into cable modem, speed test are at 13 down. (i have a 15X2).

problem is when i have my cisco plugged in i am not getting half of that ! My internet connection automatically cuts down to 4mb. I have changed duplex settings on interface, removed any crypto config. Anyone ever exp this before ?

 

[BuckWeet]

Can you provide the full config?

 

[R3AP3R]

CiSc02811#sh run
Building configuration...

Current configuration : 4906 bytes
!
version 12.4
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname CiSc02811
!
boot-start-marker
boot-end-marker
!
logging buffered 51200 warnings
no logging console
enable secret 5 $1$xEkI$Voa4oJKFO5EaG5V7MHlYp1
!
no aaa new-model
!
resource policy
!
ip subnet-zero
!
!
ip cef
no ip dhcp use vrf connected
!
ip dhcp pool lan
network 172.25.100.0 255.255.255.0
default-router 172.25.100.1
dns-server 24.93.x.x
!
!
ip domain name yourdomain.com
ip name-server 24.93.x.x
!
voice-card 0
no dspfarm
!
crypto pki trustpoint TP-self-signed-2866575237
enrollment selfsigned
subject-name cn=IOS-Self-Signed-Certificate-2866575237
revocation-check none
rsakeypair TP-self-signed-2866575237
!
!
crypto pki certificate chain TP-self-signed-2866575237
certificate self-signed 01
30820250 308201B9 A0030201 02020101 300D0609 2A864886 F70D0101 04050030
31312F30 2D060355 04031326 494F532D 53656C66 2D536967 6E65642D 43657274
69666963 6174652D 32383636 35373532 3337301E 170D3038 30353233 30313433
35315A17 0D323030 31303130 30303030 305A3031 312F302D 06035504 03132649
4F532D53 656C662D 5369676E 65642D43 65727469 66696361 74652D32 38363635
37353233 3730819F 300D0609 2A864886 F70D0101 01050003 818D0030 81890281
81009B16 D03E3DB5 2820BC56 459C3E29 0E4AD4D0 9AB4590B 9A986C82 540F2B1E
13F59327 38677D67 B3AF3C22 CC96A1AE FD780BF5 68FF915B E52ADFD3 9D0A5E67
F2CC785E EB4D4B64 ECB6BB92 6C0EC8C5 492A3E17 704CE039 07FB8396 50871099
F25763B6 D06EEBFE D09E6AE3 19BB8A89 31507F47 6259FF7A 4D9F5952 6123C00A
EACD0203 010001A3 78307630 0F060355 1D130101 FF040530 030101FF 30230603
551D1104 1C301A82 18436953 63303238 31312E79 6F757264 6F6D6169 6E2E636F
6D301F06 03551D23 04183016 80140CC7 8505FC5F 81EB459B 2CD01E52 CA2C31B2
7885301D 0603551D 0E041604 140CC785 05FC5F81 EB459B2C D01E52CA 2C31B278
85300D06 092A8648 86F70D01 01040500 03818100 40AE0E09 29F42A15 47BFE90E
C4772175 151BF833 8D020B14 0F934225 EEB6CF1D 51D7FFF5 491AD463 B2AED4B3
C11FF709 11CE438A 174B5553 59CE1E2E A8686494 DBA05F42 02D59788 9B8078B4
23C59A68 AD440E2D 3E5B312D BEFF4590 649ED0B2 16AB5F25 E5CD02F3 37708A1D
DD6B8D7E E3926828 A4714D60 EB71F4D1 DACA6B89
quit
!
!
!
!
interface Tunnel0
ip address 10.0.0.2 255.255.255.0
tunnel source FastEthernet0/0
tunnel destination 71.40.x.x
!
interface FastEthernet0/0
description Wan Link (.1)
ip address dhcp
ip nat outside
duplex full
speed 100
!
interface FastEthernet0/1
ip address 172.25.100.1 255.255.255.0
ip nat inside
duplex full
speed 100
!
interface FastEthernet1/0
!
interface FastEthernet1/1
!
interface FastEthernet1/2
!
interface FastEthernet1/3
!
interface FastEthernet1/4
!
interface FastEthernet1/5
!
interface FastEthernet1/6
!
interface FastEthernet1/7
!
interface FastEthernet1/8
!
interface FastEthernet1/9
!
interface FastEthernet1/10
!
interface FastEthernet1/11
!
interface FastEthernet1/12
!
interface FastEthernet1/13
!
interface FastEthernet1/14
!
interface FastEthernet1/15
!
interface Vlan1
no ip address
!
interface Async0/0/0
no ip address
!
interface Async0/0/1
no ip address
!
interface Async0/0/2
no ip address
!
interface Async0/0/3
no ip address
!
interface Async0/0/4
no ip address
!
interface Async0/0/5
no ip address
!
interface Async0/0/6
no ip address
!
interface Async0/0/7
no ip address
!
interface Async0/0/8
no ip address
!
interface Async0/0/9
no ip address
!
interface Async0/0/10
no ip address
!
interface Async0/0/11
no ip address
!
interface Async0/0/12
no ip address
!
interface Async0/0/13
no ip address
!
interface Async0/0/14
no ip address
!
interface Async0/0/15
no ip address
!
interface Async0/1/0
no ip address
!
interface Async0/1/1
no ip address
!
ip classless
ip route 0.0.0.0 0.0.0.0 71.42.x.x
ip route 10.0.0.0 255.255.255.0 Tunnel0
ip route 172.25.10.0 255.255.255.0 Tunnel0
ip route 192.168.10.0 255.255.255.0 Tunnel0
!
!
no ip http server
ip http authentication local
ip http secure-server
ip http timeout-policy idle 60 life 86400 requests 10000
ip nat pool voip 172.25.10.3 172.25.10.3 netmask 255.255.255.0 type rotary
ip nat inside source list 5 interface FastEthernet0/0 overload
ip nat inside destination list 100 pool voip
!
access-list 5 permit 172.25.100.0 0.0.0.255
access-list 23 permit 10.10.10.0 0.0.0.7
access-list 100 permit udp any any range 5060 5063
access-list 100 permit udp any any range 10000 20000
!
!
!
control-plane
!
!
!
!
!
!
!
!
!
line con 0
login local
line aux 0
line 0/0/0 0/0/15
line 0/1/0 0/1/1
stopbits 1
speed 115200
flowcontrol hardware
line vty 0 4
privilege level 15
password *
login
transport input telnet ssh
line vty 5 15
access-class 23 in
privilege level 15
login local
transport input telnet ssh
!
scheduler allocate 20000 1000
!
end

 

[R3AP3R]

Problem Solved :

Changed duplex and speed settings to default on BOTH fa ports going to switch / cable modem and now im getting the correct speeds.

If anyone experiences this problem, first thing i would suggest is to check duplex / speed settings on ports connecting to your cable modem & switch.

Issued the following commmands on each fa port.

router(config)# no duplex full
router(config)# no speed 100

With changes made i am now getting 14mb down.

alex

 

[GottaBeKiN]

Why can't you use auto detect for the duplex?

 

[burtsbees]

The auto duplex protocol can be different from different devices (I.E. cable modems), and the Cisco may not detect the settings properly.

Burt

 

[R3AP3R]

auto duplex was the only way that i was able to get the correct speeds off my cable modem

 

[jneiberger]

AUTO is the correct setting. You were getting a duplex mismatch before because you were hard setting the speed and duplex. This can cause a mismatch when connected to devices that still expect to see autonegotiation.

Always use AUTO unless you know you're connecting to a device that doesn't support it.