Home Lab Network Redesign Part 2: The Edge Routers

As I have never used a Mikrotik router before, there was quite a big learning curve.

I’ve only really used Cisco/Juniper like interfaces to configure routers, and I’m a fan of them. Even though I have gotten a little more used to the RouterOS command line, I must say I’m not a huge fan of it. Most of the reasons are quite minor reasons, but some of the reasons I don’t really like it is:

  • I find it silly how the menus are structured. For example, I have to first configure an interface in “/interface” context first, then switch context to “/ip address” to add an IP address. Same goes for just getting an IP from a DHCP server. To do this, you can’t do it from the “/ip address” context, but rather “/ip dhcp-client” context. There are many other cases of this, and while none of this is really a big deal, I find it is quite inconvenient. I want to configure the options for a single interface in one place.
  • There are a lot of little things I think ROS is lacking. For example, creating a GRE tunnel from the “/interface gre” context, you have to provide a local-address to source the packets from. This is a pain because if you are on a dynamic IP address, it involves an extra step of editing the address every time your address changes. On Cisco routers, you can just do “tunnel source $INTERFACE” and it’ll automagically use the correct source address. This is also for adding routes via the DHCP provided default gateway. On IOS, I can just do “ip route dhcp” to route some packets explicitly via the DHCP assigned default gateway. This is useful because in order to reach my dedicated server, I need a single route via my DHCP assigned default gateway, before BGP from my dedicated server pushes down a new default route. In ROS you can’t do this, and have to add a static route manually yourself, and edit it each time your address changes. Again, these are minor things, but I’m sure there are some bigger things which I cannot remember at the moment.

To be fair, these reasons are quite minor, and considering the price difference between a Mikrotik router, and a Cisco/Juniper router, I guess it is acceptable.

In terms of setting up the RB2011UAS-RM, I wanted to keep the config as simple as possible:

  • Make the DHCP client add the default route with a distance of 250. This allows the default route pushed from my dedicated server have priority, and be the active route.
  • Add a static route to my dedicated server via the DHCP assigned default gateway.
  • Setup VRRP on the “inside” interfaces of both edge routers
  • Setup GRE tunnels back to my dedicated server
  • Configure BGP between both edge routers to the dedicated server, and BGP peering to each other via the point-to-point connection.
  • Added static routes to my internal network behind my ASAs.

I didn’t want to add any masquerading/NAT rules on the edge routers, because I felt it’ll add extra CPU load for no reason since the default route will be via the dedicated server, and NAT will be done there, but I dedicated it might be better to just add a rule to NAT any traffic going straight out to the internet (not via the GRE tunnels) just incase for whatever reason, the BGP sessions on both routers were down, and traffic was no longer going via my dedicated server.

That’s pretty much it for the edge routers. It’s simple, and it’s working well so far!

Again, I can share config files if anyone wants to look at them!

Home Lab Network Redesign Part 1: The Remote Dedicated Server

Home Lab Diagram
As promised, here is a very very basic diagram of my home lab. This is quite a high level overview of it, and the layer 2 information is not present as I suck at Visio, and all the connectors were getting messy on Visio with the layer 2 stuff present! What is not shown in the digram:

  1. There are two back-to-back links between the edge routers which are in an active-passive bond.
  2. Each edge router has two links going into two switches (one link per switch), both these links are in an active-passive bonded interface.
  3. The two edge firewalls only have two links going to each of those switches. One port is in the “inside” VLAN, and the other is on the “outside” VLAN. I wanted to have two links per VLAN, going to both switches, but the Cisco ASAs don’t do STP, or Port-Channels so I having two links would have made a loop.
  4. The link between the two ASAs is actually going through a single switch on a dedicated failover VLAN. From reading around, the ASAs go a little crazy sometimes if you use a crossover cable as the secondary will see it’s own port go down as well in the event the primary fails. It seems that this can cause some funny things to happen. Using a switch between them means that if the primary goes down, the secondary ASA’s port will still stay up avoiding any funnyness.
  5. The core gateway only has two interfaces, each going two a different switch. One port is on the “inside” VLAN that the firewalls are connected to, and the other port is a trunk port with all my other VLANs. This isn’t very redundant, but I’m hoping to put in a second router when I have some more rack space and use HSRP to allow high availability.

As I mentioned in my previous post, I have a dedicated server hosted with Rapid Switch, through I wanted to route all my connections. There were a few reasons I wanted to do this:

  1. Without routing through the dedicated server, if one of my internet connections went down, and I failed over to the other, then my IP would be different from my primary line. This will mess up some sessions, and create a problem for DNS as I can only really point records at one line or the other.
  2. My ISP only provides dynamic IP addresses. Although the DHCP lease is long enough to not make the IP addresses change often, it’s a pain updating DNS everywhere on the occasions that it does change. Routing via my dedicated server allows me to effectively have a static IP address, I only really need to change the end point IPs for the GRE tunnels should my Virgin Media provided IP change.
  3. I also get the benefit of  being able to order more IPs if needed, Virgin Media do not offer more than one!
  4. Routing via my dedicated server at Rapid Switch also has the benefit of keeping my IP even if I change my home ISP.

The basic setup of the dedicated server is as follows:

  1. There is a GRE tunnel going from the dedicated server (diamond) to each of my edge routers. Both GRE tunnels have a private IPv4 address, and an IPv6 address. The actual GRE tunnel is transported over IPv4.
  2. I used Quagga to add the IPv6 address to the GRE tunnels as the native RedHat ifup scripts for tunnels don’t allow you to add an IPv6 address through them.
  3. I used Quagga’s BGPd to create a iBGP peering over the GRE tunnels to each of the Mikrotik routers, and push down a default route to them. The edge routers also announced my internal networks back to the dedicated server.
  4. I originally wanted to use eBGP between the dedicated servers and the edge routers, but I was having some issues where the BGP session wouldn’t establish if I used different ASNs. I’m still looking into that.
  5. There are some basic iptables rules just forwarding ports, doing NAT, and a cleaning up some packets before passing them over the GRE tunnel, but that’s all really.

Other than that, there isn’t much to see on the dedicated server. It’s quite a simple setup on there. If anyone would like to see more, I can post any relevant config.

Home Lab Network Redesign with Mikrotik Routers

I have two cable connections from Virgin Media coming into my house due to some annoying contract problems.

I originally had one line on the 60Mbit package, and the other on 100mbit, but when Virgin Media upgraded me to 120mbit I downgraded the 60mbit line to 30mbit to reduce costs.

Since I got into this strange arrangement with Virgin Media, I have been using a Cisco 1841 Integrated Services Router on the 30mbit line, and a Cisco 2821 Integrated Services Router on the 120mbit line, but I found that I wasn’t able to max out the faster line using the Cisco 2821 ISR. Looking at Cisco’s performance sheet, the Cisco 2821 ISR is only really designed to support lines of up to around 87 mbit.

So naturally, it was time to upgrade! Initially I wanted to get a faster Cisco router, but looking at the second generation ISRs, it’ll be a bit pricey!

I did actually upgrade all my 7204 VXRs to have NPE-400 modules, which according to the performance sheet should do around 215 mbits, but the 7204s are extremely loud, and I only switch them on when I am using them.

Michael and Jamie have always been talking about Mikrotik routers so I figured since Cisco is a no go, I’ll give Mikrotik a chance. I ended up buying two RouterBOARD 2011UAS-RM from WiFi Stock.

To put the RB-20011UAS-RM boxes in, I decided I was going to restructure my network a bit. I will be making a series of posts discussing my re-designed network.

My goals for the redesign were as follows:

  • The RB-2011UAS-RM boxes will only function as edge routers, encapsulating traffic in GRE tunnels, and that’s all.
  • There will be a link between both edge routers, with a BGP peering for redirecting traffic should one of my lines go down.
  • They will have GRE tunnels to all my dedicated servers/VPSs.
  • I will use Quagga on all dedicated servers, and VPSs outside my network to create BGP peerings with my edge routers.
  • I wanted to route all my internet out of a server I currently have hosted with Rapid Switch, so BGP on the RapidSwitch box (called diamond) will have to push down a default route.
  • I wanted to use my Cisco ASA 5505 Adaptive Security Appliance as firewalls between the edge routers and the core.
  • I recently bought a Cisco 2851 Integrated Services Router, which I will use as a “core” router.
  • I wanted as much redundancy as possible.

In my next post I will create a diagram of what I will be doing, and discussing the setup of the server I have hosted at RapidSwitch.

As I have never used Mikrotik routers before, I will also attempt to discuss my experiences of RouterOS so far as I go along.