I have a Cisco 3945E 15.4(3)M1 (Upgraded from a 2851) Router connected to the internet via a cable modem using dhcp. This router, in turn connects via a plain GRE tunnel to a cloud instance and on to the internet.
The tunnel and endpoints are up and running. Traffic flows in both directions and routes properly. I have a 400 mb/s pipe at the Cisco end and a much larger one at the cloud instance end. I was using LISP before in a similar situation and was getting 300+ mb/s. With the new setup (Either Router!)I am down to 50 mb/s. I MUST have a misconfig issue someplace. I have checked CPU load on the router (<30%) and nload on the Linux Instance (Centos 7) shows the 50 mb/s with essentially zero CPU load.
I have calculated and deployed an MTU of 1476 for the Tunnel and 1436 as the MSS on both sides. (Client machines are still at 1500 default)
My newest basic configs are:
I am also using BGPD(FRR on the Cloud Instance) to announce a /24 publicly and routing that /24 through the Tunnel (201.x.x.x)
I changed the numbers for security purposes...
Cisco 3945E Config:
interface Tunnel0
bandwidth inherit
ip address 192.0.2.2 255.255.255.252
ip mtu 1476
ip tcp adjust-mss 1436
tunnel source 67.xxx.xxx.xxx.186 (Our Spectrum Assigned IP from Gig0/0)
tunnel destination 173.xxx.xxx.xxx (Our Virtual Instance IP Adress of the Centos 7 Box)
tunnel path-mtu-discovery
!
interface GigabitEthernet0/0
description connection to Spectrum (DHCP)
ip address dhcp
duplex auto
speed auto
!
interface GigabitEthernet0/1
description Connection to 24-port unmanaged switch 201 LAN
ip address 203.xxx.xxx.xxx.1 255.255.255.0 (Our IP/24)
ip tcp adjust-mss 1400
duplex auto
speed auto
no mop enabled
ip route 0.0.0.0 128.0.0.0 Tunnel0
ip route 128.0.0.0 128.0.0.0 Tunnel0
ip route 173..xxx.xxx.xxx.xxx 255.255.255.255 67.xxx.xxx.1 (From CENTOS box To Spectrum Modem)
end
It does work....just the speed is way off....
Essentially, I have a Instance announcing our /24 to the world via BGP. That /24 is sent down the tunnel and to the Cisco and routed to the appropriate machines on the LAN.
Used to work fantastically using LISP, even o the 2851. Now using, an allegedly simpler, system, it's very slow.
Thanks,
David
