myITmicroblog

Recently I worked on one project where a client requested to re-route web traffic to the GRE tunnel to perform traffic inspection. I would like to share with you what is required if you configure it on FortiGate. We need a new GRE interface and policy base routing (PBR) to change the route for specific source IPs. Of course you need firewall policies to permit the traffic. Let's start with GRE interface. Unfortunately you can't configure it using the GUI, only CLI is the option: config system gre-tunnel edit "gre1" set interface "port1" set local-gw 55.55.55.55 set remote-gw 44.44.44.44 next end When the end peer is Cisco router, you need to set the IP for the GRE interface: config system interface edit gre1 set ip 192.168.10.10 255.255.255.255 set remote-ip192.168.10.20 end In next step we need to fix routing. We need the alternate path via GRE but to keep the route in the active routing table you need to set the same AD (adminis...

Today I would like to test an integration of DMVPN and GET VPN technologies. DMVPN can be used over the public network like Internet and GET VPN only over private like MPLS (because of IP preservation). As you remember from my previous posts about DMVPN the best option is the phase 3. With thousands of spokes your hub has to keep the same number of SAs (security association). As you remember, for the phase 3, the first packet was sent to the hub and then was redirected (NHRP) to the destination. Next packets were sent directly to the spoke: R2 #traceroute 100.33.33.33 source 100.22.22.22 Type escape sequence to abort . Tracing the route to 100.33 . 33.33 1 10.10 . 10.1 40 msec 56 msec 76 msec 2 10.10 . 10.3 104 msec 88 msec 140 msec R2 # R2 #traceroute 100.33.33.33 source 100.22.22.22 Type escape sequence to abort . Tracing the route to 100.33 . 33.33 1 10.10 . 10.3 104 msec 104 msec 72 msec R2 # Let’s test how it works with GET VPN: ...

Today I’m going to test a phase 3 with EIGRP. To present all differences, pros, cons I have changed LAN’s IP addresses ( I strongly recommend to read my previous posts about different variances of DMVPN) : Before I start configuring the phase 3 I would like to show some limitations of the phase 2. As you know for phase 2 we can’t summarize what means every spoke needs to keep all spoke routers in its routing table to be able to establish spoke-to-spoke communication. Let’s test it on my example: R1:   ! interface Loopback0 ip address 100.11 . 11.11 255.255 . 255.0 ! router eigrp 1 network 10.10 . 10.0 0.0 . 0.255 network 100.11 . 11.0 0.0 . 0.255 no auto - summary ! R2:   ! interface Loopback0 ip address 100.22 . 22.22 255.255 . 255.0 ! router eigrp 1 network 10.10 . 10.0 0.0 . 0.255 network 100.22 . 22.0 0.0 . 0.255 no auto - summary ! R3:   ! interface Loopback0 ip address 100.33 . 33.33 255.255 . 255.0 ! ro...

The phase two allows me on spoke-to-spoke communication. Please read my previous post (EIGRP phase one): http://myitmicroblog.blogspot.com/2014/12/dmvpn-phase-one-eigrp.html You should know the phase two is not recommended because the phase three solves many issues like scalability. I will describe the differences between them in my next post. From the configuration perspective I need to change: R1 (hub):   interface Tunnel0 no ip next - hop - self eigrp 1 Let’s check the settings on R2 before we send traffic:   R2 #sh ip route eigrp 33.0 . 0.0 / 24 is subnetted , 1 subnets D 33.33 . 33.0 [ 90 / 310172416 ] via 10.10 . 10.3 , 00 : 22 : 35 , Tunnel0 D 11.0 . 0.0 / 8 [ 90 / 297372416 ] via 10.10 . 10.1 , 00 : 22 : 37 , Tunnel0 R2 # As you see the next hop for Lan3 (33.33.33.33) is R3 not R1 like with the phase one.   R2 #sh ip nhrp 10.10 . 10.1 / 32 via 10.10 . 10.1 , Tunnel0 created 01 : 40 : 18 , never expire T...