Internet Speed

muneef81 · ‎05-17-2020

hey all

I have Xfinify modem/router with 600MB download i did conncent a gig Cisco 1921 router to be my defalt gateway and i connected to cisco router cisco gig switch 3750G, my problem here when i connect my computer to xfinity router i will get the full 500 mb download, but when i connect my pc to the Cisco switch or router i am gettting 250 md only, why am not getting the full speed when i am connected to my cisco switch and router ?

H1B#show ip int brief
Interface IP-Address OK? Method Status Protocol
Embedded-Service-Engine0/0 unassigned YES NVRAM administratively down down
GigabitEthernet0/0 10.0.0.84 YES DHCP up up
GigabitEthernet0/1 172.20.0.1 YES NVRAM up up
Serial0/1/0 unassigned YES NVRAM administratively down down
GigabitEthernet0/0/0 unassigned YES unset down down
GigabitEthernet0/0/1 unassigned YES unset down down
GigabitEthernet0/0/2 unassigned YES unset down down
GigabitEthernet0/0/3 unassigned YES unset down down
NVI0 unassigned YES unset administratively down down
Vlan1 unassigned YES unset down down
Vlan20 172.20.1.1 YES NVRAM down down
Vlan99 unassigned YES unset down down

H1B#show run
Building configuration...

Current configuration : 2558 bytes
!
! No configuration change since last restart
version 15.2
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname H1B
!
boot-start-marker
boot-end-marker
!
!
enable secret 4 9x4aQYg4ZVk1FUMaleimpgDuciy.gApNdVdNbwt4R0fgw8wffw
!
no aaa new-model
clock timezone EST -5 0
clock summer-time EDT recurring
!
ip cef
!

ip dhcp excluded-address 172.20.0.1 172.20.0.10
ip dhcp excluded-address 172.20.1.1 172.20.1.10
!
ip dhcp pool LAN
network 172.20.0.0 255.255.255.0
default-router 172.20.0.1
dns-server 75.75.75.75 4.2.2.2
!
ip dhcp pool WIFI
network 172.20.1.0 255.255.255.0
default-router 172.20.1.1
dns-server 75.75.75.75 4.2.2.2
!

ip domain name cisco.com
no ipv6 cef
!
multilink bundle-name authenticated
!
license udi pid CISCO1921/K9 sn FTX173985GZ
!
username it secret 4 9g4oYgZbVk1FUMale5impgzDuciy.gApN5dVdNbw9t4R0fg2w
!
redundancy
!

ip ssh version 2
!
interface Embedded-Service-Engine0/0
no ip address
shutdown
!
interface GigabitEthernet0/0
ip address dhcp
ip nat outside
ip virtual-reassembly in
duplex auto
speed auto
!
interface GigabitEthernet0/1
ip address 172.20.0.1 255.255.255.0
ip nat inside
ip virtual-reassembly in
duplex auto
speed auto
!
interface Serial0/1/0
no ip address
shutdown
!
interface GigabitEthernet0/0/0
switchport access vlan 20
no ip address
!
interface GigabitEthernet0/0/1
switchport access vlan 20
no ip address
!
interface GigabitEthernet0/0/2
switchport access vlan 20
no ip address
!
interface GigabitEthernet0/0/3
switchport access vlan 20
switchport trunk native vlan 99
switchport mode trunk
no ip address
!
interface Vlan1
no ip address
!
interface Vlan20
ip address 172.20.1.1 255.255.255.0
ip nat inside
ip virtual-reassembly in
!
interface Vlan99
description Native
no ip address
!
ip forward-protocol nd
!
no ip http server
no ip http secure-server
!
ip nat inside source list 2 interface GigabitEthernet0/0 overload
!
access-list 2 permit 172.20.0.0 0.0.0.255
access-list 2 permit 172.20.1.0 0.0.0.255
access-list 2 deny any
!
control-plane
!
line con 0
line aux 0
line 2
no activation-character
no exec
transport preferred none
transport output pad telnet rlogin lapb-ta mop udptn v120 ssh
stopbits 1
line vty 0 4
password bob
login local
transport input all
line vty 5 15
password bob
login local
transport input all
!
scheduler allocate 20000 1000
ntp server 216.239.35.0
!
end

balaji.bandi · ‎05-17-2020

check the throhghtput report of your model.

BB

***** Rate All Helpful Responses *****

How to Ask The Cisco Community for Help

Richard Burts · ‎05-17-2020

There are multiple things that might impact the speed that you get. When you tested was your PC connected to a switch port or connected directly to router? If there was possibly a duplex mismatch it would impact the speed. Would you post output of show interface for both router Ethernet interfaces? Running services like nat will have some impact.

HTH

Rick

Georg Pauwen · ‎05-17-2020

Hello,

on a side note, you need a default route. Add the below to your configuration:

ip route 0.0.0.0 0.0.0.0 GigabitEthernet0/0 dhcp

paul driver · ‎05-17-2020

Hello

Just like to add I think could be down to the the switch throughput port capability i've not checked it on yet but I wouldn't be surprised on 3750 if it to can full duplex any more then 250mb on a gig interface.

Please rate and mark as an accepted solution if you have found any of the information provided useful.
This then could assist others on these forums to find a valuable answer and broadens the community’s global network.

Kind Regards
Paul

Joseph W. Doherty · ‎05-17-2020

Although the 3750G cannot support wire speed on all ports, it should be able to easily support gig on a single port.

The 3750G has a 32 Gbps fabric, sufficient for 16 gig (duplex) ports at line rate. It also provides 38.7 Mpps, which would support 26 Gbps. The fabric will be the performance bottleneck.

Joseph W. Doherty · ‎05-17-2020

The most likely bottleneck is your router. Since you're doing PAT on it, take particular notice to table 6 in the reference that Balaji provided. Also take notice of the 1921's CPU performance history when you hit your maximum obtainable download speed.