topic Re: Static ECMP in Firewall and Security Management

Static ECMP

Raj_Khatri — Fri, 08 Jun 2018 13:37:04 GMT

We are trying to do ECMP with static routing and have configured 2 default routes. The "show route" command shows two default next hops, however, "netstat -r" shows only one default next hop. We currently use 2 next hops and the ping feature to determine next hop status which seems to work well. Does anyone know if this is achievable to load balance using statics for default route? I know this can be done using eBGP...

Sample CLI output -

#show route
S 0.0.0.0/0 via 1.1.1.1, eth3-01, cost 0, age 767583
via 1.1.1.2, eth3-01

#netstat -r
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
default 1.1.1.1 0.0.0.0 UGD 0 0 0 eth3-01

Re: Static ECMP

PhoneBoy — Fri, 08 Jun 2018 16:14:37 GMT

Yes, this is supported, but you need to configure the maximum number of path splits in Gaia.

Configuring Equal Cost Path Splitting - Gaia Portal

In the tree view, click Advanced Routing > Routing Options.
In the Equal Cost Multipath section, select the Maximum Paths.
Click Apply.

Re: Static ECMP

Raj_Khatri — Mon, 11 Jun 2018 11:56:54 GMT

Changed from default setting of 8 down to 2 and still shows the same in 'netstat -r | grep default'

Re: Static ECMP

PhoneBoy — Mon, 11 Jun 2018 15:21:35 GMT

It's possible what you're seeing is expected.

Sundeep Mudgal‌, any thoughts?

Re: Static ECMP

Sundeep_Mudgal — Mon, 11 Jun 2018 15:44:11 GMT

netstat might have a bug. Please try "ip r' command in expert mode.

Re: Static ECMP

Raj_Khatri — Tue, 12 Jun 2018 13:23:13 GMT

Sundeep, I do see both static default routes when running "ip r" So it does seem like a bug with "netstat -r" output. We have an open case with TAC who is also checking with R&D. Thanks again.

fw> show route static

S 0.0.0.0/0 via x.x.x.230, eth3-01, cost 0, age 514897
via x.x.x.231, eth3-01

[Expert@fw:0]# netstat -r | grep default
default x.x.x.230 0.0.0.0 UGD 0 0 0 eth3-01

[Expert@fw-:0]# ip r
default proto routed
nexthop via x.x.x.230 dev eth3-01 weight 1
nexthop via x.x.x.231 dev eth3-01 weight 1