Comcast Bussiness Class and GRE Tunnels

Nate Burke nate at blastcomm.com
Tue Jul 26 16:46:55 UTC 2011


Thanks for all the replies, I have all the firewalls disabled on the SMC 
Modem, with my Static IP set on the Mikrotik.  The PPTP Tunnel came up 
and ran just fine when I configured it, it was working great when I left 
the office last night, but this morning It was running very slow.  I 
just setup an IPIP tunnel, and did my EOIP tunnel over that, and it came 
right up, we'll see if it's still working in a few hours.

Nate


On 7/26/2011 10:45 AM, Jon Bane wrote:
> On Tue, Jul 26, 2011 at 11:38 AM, PC<paul4004 at gmail.com>  wrote:
>
>> I have GRE tunnels and l2tp tunnels over those comcast boxes.  l2tp is less
>> hassle because it handles NAT, but you can do GRE instead -- just make sure
>> you assign yourself a public static IP.
>>
>> First, go into the gateway and make sure all firewalls are disabled (it has
>> a web GUI).
>>
>> Second, if it's the comcast SMC 4 port "gateway" thing I think it is, the
>> device is somewhat retarded.  You plug into the switch and pull DHCP, and
>> you get a natted address and it routes.
>>
>> You can plug into the same switch and set a static IP on your device
>> (internet public IP), and it will work without NAT, assuming your account
>> has a static IP.
>>
>> Set said static IP on your microtik box and it should pass end-to-end
>> without drops.
>>
>>
> Was working on the same reply as Paul.  You assign your static to your
> Mircotik box and check the box in the WebGUI (default is http://10.1.10.1)
> to "Disable Firewall for True Static IP Subnet Only" on the firewall tab.
>
> -Jon




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