Hi Mark, The default gateway of the machine is the EX4500.
I have since tried another scenario. If I place both ISPs on the same MX80, and the same asymmetric route exists on the ingress and egress, there is no longer an issue with connectivity. I only have an issue when the ingress and egress paths traverse different MX80 devices. Thank you, Chad > Subject: Re: [j-nsp] Asymmetric Routing > To: [email protected]; [email protected] > From: [email protected] > Date: Tue, 13 Oct 2015 08:07:36 +0200 > > > > On 13/Oct/15 04:56, Chad Levy wrote: > > > Hi all, > > > > I am having an issue with a new set of Juniper MX80 routers and an EX4500 > > switch. My topology is extremely simple, each MX80 has its own internet > > provider running full BGP routes, and iBGP between the two. The EX4500 is > > connected to both MX80 devices with /30 P2P running OSPF with route > > redistribution. The MX80s are originating a default route to the EX4500 via > > OSPF. > > > > I have a single /24 announced to both of my internet providers with a > > machine connected to the EX4500 via a /30. > > > > Both MX80 devices can ping the machine, and vice-versa. My issue becomes > > when I have an inbound route traverse "ISP A" on one MX, but the return > > path tries to egress "ISP B" on the other MX. Traffic is dropped and never > > reaches its final destination. The same behavior happens when the ingress > > is on "ISP B" and egress on "ISP A". > > > > If the ingress and egress paths are symmetrical, connectivity is fine. > > Additionally, if I override the OSPF learned route for the machines /30 on > > the ingress MX80, and point a static route to the egress path MX80 for the > > /30, traffic flows perfectly fine. > > > > I do not have any elaborate firewall filters or anything such as RPF > > enabled, etc on any of the devices at this time. My carriers are also not > > filtering any traffic on their side. > > > > Are there any default configurations in place on either the MX80 or EX4500 > > that could cause this behavior? One MX80 is running JunOS 13.3, the second > > MX and the EX4500 are both running JunOS 12.3. The behavior is similar to > > using a pair of SRX devices in flow mode with traffic ingress on one > > device, and egress on another. > > What is the PC's default gateway? The MX80's or the EX4500? > > Mark. _______________________________________________ juniper-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/juniper-nsp
