Description

Trying to build a IP-IP tunnel from Azure hosted vSRX to MX240 device, The interface comes up and am able to ping the remote side however not the tunnel IP.

Symptoms

The following messages appear in /var/log/messages:

Aug 7 12:26:20 vsrx01 IFP error> ../../../../../../../../../src/pfe/usp/control/applications/interface/ifp.c@2509:(errno=100) create/update ipip tunnel failed 1

Aug 7 12:26:20 vsrx01 IFP error> ../../../../../../../../../src/pfe/usp/control/applications/interface/ifp.c@3393:(errno=100) tunnel session add(ip-0/0/0) failed

 

The following configuration is done on the vSRX side.

 

set security zones security-zone trust interfaces ip-0/0/0.0

set security zones security-zone trust interfaces ge-0/0/1.0

set security zones security-zone untrust interfaces ge-0/0/0.0

set interfaces ge-0/0/0 unit 0 family inet address x.x.x.x/29

set interfaces ip-0/0/0 unit 0 tunnel source y.y.y.y

set interfaces ip-0/0/0 unit 0 tunnel destination a.a.a.a

set interfaces ip-0/0/0 unit 0 tunnel path-mtu-discovery

set interfaces ip-0/0/0 unit 0 family inet address a.b.c.d/30

set interfaces ge-0/0/1 unit 0 family inet address y.y.y.y/28

set interfaces fxp0 unit 0

set routing-instances VR1 interface ge-0/0/0.0

set routing-instances VR1 interface ip-0/0/0.0

set routing-instances VR1 interface ge-0/0/1.0

 

 

user@router> show interfaces terse | match "ge-|ip-"

ge-0/0/0 up up

ge-0/0/0.0 up up inet x.x.x.x/29

ip-0/0/0 up up

ip-0/0/0.0 up up inet a.b.c.d/30

ge-0/0/1 up up

ge-0/0/1.0 up up inet y.y.y.y/28

 

 

 

user@router> show route

inet.0: 3 destinations, 3 routes (3 active, 0 holddown, 0 hidden)

+ = Active Route, - = Last Active, * = Both

 

...............

VR1.inet.0: 8 destinations, 8 routes (8 active, 0 holddown, 0 hidden)

+ = Active Route, - = Last Active, * = Both

 

0.0.0.0/0 *[Static/5] 00:59:18

> to y.y.y.b via ge-0/0/0.0

.................

a.b.c.d/30 *[Direct/0] 00:34:54

> via ip-0/0/0.0

a.b.c.d/32 *[Local/0] 00:34:54

Local via ip-0/0/0.0

 

 

user@router> ping 8.X.X.8 routing-instance VR1 count 1

PING 8.X.X.8 (8.X.X.8): 56 data bytes

64 bytes from 8.X.X.8: icmp_seq=0 ttl=56 time=80.586 ms

 

user@router> ping (remote Ip) routing-instance VR1 count 1

PING a.a.a.a (remote IP): 56 data bytes

64 bytes from a.a.a.a: icmp_seq=0 ttl=61 time=5.823 ms

 

However the remote tunnel IP is not reachable.

Solution

As per Document published by Azure, Azure does not allow GRE and IP-IP traffic in the network.

 

https://learn.microsoft.com/en-us/azure/virtual-network/virtual-networks-faq#what-protocols-can-i-use-within-vnets

 

What protocols can I use within VNets?

You can use TCP, UDP, ESP, AH, and ICMP TCP/IP protocols within VNets. Unicast is supported within VNets. Multicast, broadcast, IP-in-IP encapsulated packets, and Generic Routing Encapsulation (GRE) packets are blocked within VNets. You cannot use Dynamic Host Configuration Protocol (DHCP) via Unicast (source port UDP/68 / destination port UDP/67). UDP source port 65330 which is reserved for the host. See "Can I deploy a DHCP server in a VNet" for more detail what is and is not supported for DHCP.

 

Modification History

Document Created

Related Information

https://learn.microsoft.com/en-us/azure/virtual-network/virtual-networks-faq#what-protocols-can-i-use-within-vnets