My Customer cannot connect to their webmail from their network

[jamesp4330]

I call my self being experienced in all types of networks but this issue is throwing me for a loop.

I have a small business customer who from their network which I manage cannot connect to their domain.com including email. I can go to any WiFI location off their network and pull it up all day long.

They are on Comcast and I have logged into their router and it is wide open. The site and email are hosted on a offsite VPS account. Again I can come back to my office and connect to the site and email with no issues and I am on Comcast Internet as well.

I have checked the IP address and it is not banned on any of the sites.

I am working again for this customer after their using another tech for a short period of time. I cannot find any evidence that they have somehow blocked the connection, but I keep questioning it in the back of my mind.

What am I missing?? Thanks in advance for your help.

 

[ShinyTech]

You said they have a router and it is open but did they install a firewall, switch or security appliance?

 

[jamesp4330]

There is a Network switch and a server but no firewall yet

The only firewall is the one in the Comcast Modem and it is what I referred to as wide open. The sever is just a file server and does not control any network functions.

I can while in my office connect on my laptop but when I go to their office and try to connect with my laptop it will not connect.

 

[ComputerRepairTech]

you confirmed dns provides same ip while you are at the location? can you access website via ip?

 

[ShinyTech]

Is the domain website and email local? If it is local then the router / modem might not support loopback. Loopback allows the connection to go out then back in when accessing servers internally using an external address.

 

[jamesp4330]

I have tried connecting just using the IP address and no go. Ping test show 100% failure.

The server is offsite. I actually have another 10 accounts on that VPS server and all others connect using the same IP address all day long.

 

[SilverLeaf]

Have you tried traceroute to see where the path stops?

edit: sorry "tracert" for windows

 

[jamesp4330]

This is the info on where it stops, this last IP address.

NetRange 184.170.240.0 - 184.170.255.255
CIDR 184.170.240.0/20
Name COLOAT
Handle NET-184-170-240-0-1
Parent NET184 (NET-184-0-0-0-0)
Net Type Direct Allocation
Origin AS AS46562
Organization Colo at 55, LLC (COLOA)
Registration Date 2011-08-30
Last Updated 2012-03-02
Comments
RESTful Link http://whois.arin.net/rest/net/NET-184-170-240-0-1
See Also Related POC records.
See Also Related organization's POC records.
See Also Related delegations.

I have no clue who this is. Attached is the Tracert results.

 

[ComputerRepairTech]

Well on my test thats the last hop before the actual server. Maybe IP banned maybe something blocking that particular ip on the router i dunno

Edit: Thats a cpanel server, did you check SPF for the IP to see if its blocked some where?

 

[jamesp4330]

I have turned it over to the company that manages my VPS including the tracert results. I appreciate all your suggestions I have forgotten how valuable the tracert command was. Thanks for your help.