Tag Archives: v4.10

Bug spotting – PPPoE and Hotspot

Came across an interesting (yet to be verified) bug today.

The info:

RouterOS v4.10 running on x86 server

Site runs both a hotspot and PPPoE server on the same interface.

Users can decide to login via the captive portal (which most do) or for those who understand and wish to use a pppoe connection, they have the option to use that instead, as it comes with a public IP.

The problem:

Support call came in saying that a user was unable to access www.google.com (which for the sake of this example we’ll say resolves to 192.0.2.1). I checked and confirmed I could indeed ping and trace to the address and put it down to a user issue, but left the ticket open to have one of our on-site techs give a try.

— later on–

Onsite tech indicated he to had become unable to access www.google.com via the pppoe login option and after getting a first hop response from the gateway the connection simply timed out.

The cause:

I’ll save you from having to hear about everything I tested and tried over the next hour however the actual cause was rather interesting.

The “hosts list” on the hotspot, had old entries from someone with an improperly configured IP address (in this case 192.0.2.1) which had tried to access the login page sometime in the past couple of days and was being held there. This meant that for users connected behind the pppoe interfaces, traffic to 192.0.2.1 was trying to go to that host RATHER than going out the correct default route.

Why? No idea.

The solution:

When the hotspot was setup (we’d reinstalled the machine just recently) it appears someone had forgotten to set the ‘idle-timeout’ value on the hotspot user-profile. This meant all these hosts were being held and the table was getting larger and larger (there were other incorrect addresses in there too).

Better solution: Provided by Mikrotik support
You have an option to allow only specific subnet to reach the HotSpot network.
Add the to ip-binding, specify subnets you would like to allow and set type=regular.
Block any other unneeded subnet by type=blocked.

Eg:

/ip hotspot ip-binding
add address=10.10.40.0/21 comment="Accept (not bypass) anything in the LAN range" disabled=no
add address=0.0.0.0/0 comment="block all else" disabled=no type=blocked

Side note: We don’t use the address-pool option on the hotspots as this causes LAN traffic to pass back (and be counted by) the router which we don’t want (as we let our users have unlimited LAN access to each other) so I’m at quite a loss as to why this routing pattern would occur.

IPv6 and Mikrotik – Using 6to4

Please note this guide assumes some basic knowledge of IPv4 and IPv6 address space.

Many of you may know of the impending doom that surrounds the IPv4 network and lack of remaining IP ranges.

The question is, how many people are actually doing anything about it? Given the slow take up worldwide I thought it worthwhile I do a post here to explain how you can get IPv6 on your network now.
No support required from your upstream ISP and without having to send your traffic half way around the world to a Hurricane Electric tunnel (hopefully).

So, what is 6to4?

From: http://en.wikipedia.org/wiki/6to4

6to4 is an Internet transition mechanism for migrating from IPv4 to IPv6, a system that allows IPv6 packets to be transmitted over an IPv4 network (generally the IPv4 internet) without the need to configure explicit tunnels. Special relay servers are also in place that allow 6to4 networks to communicate with native IPv6 networks.
6to4 is especially relevant during the initial phases of deployment to full, native IPv6 connectivity, since IPv6 is not required on nodes between the host and the destination. However, it is intended only as transition mechanism and is not meant to be used permanently.

Continue reading IPv6 and Mikrotik – Using 6to4

Mikrotik Hotspot Authentication for IPv6 dual-stacked clients

In preparation for some IPv6 testing of our hotspot systems, I’ve come up with the following temporary authentication method for dual-stacked users.

Seeing as the login redirect goes via an IPv4 webserver, if enabled IPv6 traffic passes by the hotspot unhindered. This is my work on enabling the IPv6 side of things when a user logs in or out of the hotspot with a dual stacked client.

This has been implemented on my demo v4.10 router and tested with both Mac OS X 10.6 and Windows 7 Ultimate x64 Continue reading Mikrotik Hotspot Authentication for IPv6 dual-stacked clients