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webmail page blocked only on Rogers network

jhaltiga68
I plan to stick around

Recently, my workplace reconfigured their webmail browser link due to repeated phishing attacks etc. The new address was simply the old modified to include /.ext. However, every since the change, this address will not load or is blocked ONLY on my Rogers network. Why is this? I was told when I called support it is due to an ISEC 2 regulation, but I am not sure what this is all about.

 

Would appreciate any insight.

 

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Re: webmail page blocked only on Rogers network

Pauly
Resident Expert
Resident Expert

Thanks, I was going to make the suggestion that its possible your IP V4 Address has been blacklisted, you can disconnect your modem for 5 -10 mins and re-connect it and see if it acquires a NEW IP Address, or you can call rogers technical support and ask them to assign you a new one.  They use Dynamic IP Addressing at Rogers, but often the IP will be re-assigned to you once the lease expires but there's ways of getting a new one ,and new IPs usually solve man of these issues so its no point to blacklist someones IP as they will get a new one and someone else will end up with the blacklisted IP and have all sorts of issues, hope this helps

Re: webmail page blocked only on Rogers network

jhaltiga68
I plan to stick around

Pauly:

 

would this apply even if I set my DNS ipv6 manually as per datalink's earlier suggestion? (i.e., it's not auto?)

 

I may unplug the modem nonetheless and see what happens.

Re: webmail page blocked only on Rogers network

Your pc should be using temporary IPV6 addresses for internet purposes.  If you type in whatsmyip for a google search, it should show you the IPV4 and I believe the IPV6 address as well.  You can also use whatsmyip.org   The IPV4 address should be the same but I'm not sure if the IPV6 address will be displayed or if it will match up with the previously displayed IPV6 address.  

 

Then, bring up a command prompt and run an ipconfig/all command.  You should see that the whatsmyip IPV6 address matches up with one of the temporary IPV6 addresses.  

 

To see the IPV6 temporary parameters, at a command prompt, type in:   netsh interface ipv6 show privacy

That should show that the Windows system is using temporary IPV6 addresses.  

 

So, assuming that is the case, and you're blacklisted by the Web Mail server, that would indicate that the Web Mail server is using IPV4 addresses.  

 

Although Rogers uses dynamic addressing, I've found that the public address doesn't change very often, if at all.  That IP address assignment is most likely left up to automatic assignment by the CMTS and I don't believe that a modem power disconnect will change anything.  Using whatsmyip before and after will confirm or deny that thought.  I don't believe that the Tier I techs have the ability to force an IP address change.  I think this would have come up previously, although, hey, you never know.  In either case, I'd be surprised to see an IPV4 IP address change.  

Re: webmail page blocked only on Rogers network

jhaltiga68
I plan to stick around

In sum, nothing short of a new modem would seem to be the resolution here, is that correct? If I use auto select for the DNS addresses, you are suggesting that they are unlikely to change even with a hard power disconnect and the ones I currently have manually configured per your earlier recommendation are static and blocked?

Re: webmail page blocked only on Rogers network

You're mixing a couple of subjects here, the first being the blacklist issue, the second is the Domain Name Server that you choose to use on your local network, as determined by the actual Domain Name Server address that you enter into the modem.  

 

1.  It appears that the Web Mail server has blacklisted your address.  In theory this should be your address only, and not the entire IP address range that Rogers occupies.  So, when you attempt to contact the Web Mail server, that server looks up the incoming IP address and checks that address against its existing blacklist.  It would appear that your modem's WAN IP address is on that list, therefore the Web Mail server doesn't respond to any incoming traffic from your modem.  The modem's WAN IP address is determined by the Cable Modem Termination System (CMTS) which your modem is connected to.  Each CMTS has its own assigned IP address block that it can use to assign individual addresses to connected modems.  That address block doesn't appear to change all that often, and without an IP release message from your modem, the CMTS will most likely issue the same WAN IP address to your modem, as contained within its database and based on the modem MAC addresses stored within that database.  That's why I don't expect your WAN IP address to change if you unplug the modem for a period of time.  I suspect that it might take as much as 24 hours or longer without any CMTS connection before the CMTS might issue a new WAN IP address to the modem.  The shorter path to a new WAN IP address would be to just swap the modem at the nearest Rogers store.  The new modem will have a different MAC address which should result in a new WAN IP address unless there is a severe shortage of available IP addresses for your CMTS.  I've never heard of a situation where two modems were issued the same WAN IP address.  Anything's possible, but, its unlikely to happen. 

 

2.  The next issue is the Domain Name Server.  The company that hosts the Web Mail server which in this case appears to be the Centre for Addiction and Mental Health itself, is responsible for promulgating the www.xxxxxxx addresses and the  corresponding numerical IP addresses for destinations under its control.  Not sure which organization CAMMH pushes those www.  addresses and IP addresses to, but, that's not totally important.  There is a system under which those addresses are promulgated to all of the Domain Name Servers, so, it doesn't matter which Domain Name Server you use, Rogers, Google, Quad 9, etc, etc.  All of those Domain Name Servers should provide the same numerical IP address to the browser or application when you attempt to contact https://webmail.camh.net/ext.  If you leave the DNS setting on Auto, the modem and all of its connected devices will use the Rogers DNS unless you've set a particular device to a different hard set DNS address.  The CMTS will provide the modem with the appropriate Rogers DNS addresses, which the modem and its connected devices will use if Auto has been selected.  If you manually enter the addresses for Google, OpenDNS, Quad 9, etc, etc, the modem and its connected devices will use that selected DNS.  Typically the web browser will send a DNS query to the assigned Domain Name Server, or, depending on the modem or router, that request goes to the modem or router which may have the address in its own address cache.  If not, then the modem or router will send that request to the assigned DNS address as specified by the Auto setting or manually entered address.  At the end of the day, the same Web Mail server numerical IP address should be provided to the browser or application, regardless of DNS choice, and that browser or application will then attempt to contact the provided numerical IP address.  

 

At this point the problem arises where the server at that address is rebuffing your attempts to contact it, based on your modem's WAN IP address.  If you had a router this would be easy to solve by cloning a MAC address from your local network at which point the router uses that local MAC address as its external MAC address.  End result, a new WAN IP address issued by the CMTS.  That should resolve situations like this as well.  

 

So, at the end of the day, having seen this a few times before, my recommendation is to swap the modem as that is usually the quickest way to resolve the situation.  

 

The other way to potentially resolve this is to contact the IT administrator for CAMMH to see if he or she can resolve the situation.  Typically the blacklists are machine generated or downloaded from blacklist sources, so the IT staff probably doesn't get involved in the day to day maintenance of that blacklist.  

 

Hope this helps....

Re: webmail page blocked only on Rogers network

jhaltiga68
I plan to stick around

Massive post full of info. Most grateful for this wealth of info and razor sharp attention to providing the utmost detail.

Re: webmail page blocked only on Rogers network

there should be absolutely no need to swap your modem to solve this, your modem gets a WAN IP from Rogers, the modems get ip addresses dynamically, there should be an easy way to flush and release and renew this, if not from your end it should be able to from rogers tech supports end.   

 

swapping modem is like buying a new car when your car ran out of gas, its an unnecessary task to do because it is not the proper solution, and adds to the cost of technical support which might cause price increases down the road which we do not want

Re: webmail page blocked only on Rogers network

jhaltiga68
I plan to stick around

Does a hard reset on the modem flush it?

Re: webmail page blocked only on Rogers network

I personally don't believe so.  Use whatsmyip to check, before and after a factory reset.  

Re: webmail page blocked only on Rogers network

drjohnst
I plan to stick around

https://performance.cira.ca/ on top of being a speedtest site also checks your dnssec. Since it was mentioned that you are not using standard rogers dns, you should be very careful, as this puts you at the mercy of whoever is running them. That said, be careful with googles dns (8.8.8.8, 8.8.4.4) as they are a nice alternative, but I have personally had issues with them and encryption on websites in the past(exactly as you describe above). 

 

Also, scan your system with malwarebytes as some malware will hijack your dns and may cause problems like you are describing. 

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