Routing

Dear Juniper,

I am curious about the "next-table" option of "static routing".

The topology is as follows.

First, the below config is committed.
"set routing-options static route 33.33.33.0/24 next-table VRF10.inet.0"

After that, when I commit the below config, an error occurs.
"set routing-instances VRF10 routing-options static route 11.11.11.0/24 next-table inet.0"

[edit]
root@XM1# commit
error: [rib inet.0 routing-options static]
next-table may loop
error: configuration check-out failed"

I searched on the internet and it says it's because of "loop protection".

I'm curious about the conditions under which loop protection occurs (when it occurs).

And is it impossible to communicate between different routing instances with only static routing?

Hello,

You can configure a static route with the next-table option from a VRF table to inet.0, or from inet.0 to a VRF table. However, in both cases, there's a risk of creating a routing loop.

For example, if you configure a default route (0.0.0.0/0) in a VRF pointing to inet.0, and then configure another default route in inet.0 pointing back to the VRF using next-table, this would cause a routing loop. To prevent such situations, Junos enforces loop protection and rejects the configuration.

Dear Juniper,

I am curious about the "next-table" option of "static routing".

The topology is as follows.

First, the below config is committed.
"set routing-options static route 33.33.33.0/24 next-table VRF10.inet.0"

After that, when I commit the below config, an error occurs.
"set routing-instances VRF10 routing-options static route 11.11.11.0/24 next-table inet.0"

[edit]
root@XM1# commit
error: [rib inet.0 routing-options static]
next-table may loop
error: configuration check-out failed"

I searched on the internet and it says it's because of "loop protection".

I'm curious about the conditions under which loop protection occurs (when it occurs).

And is it impossible to communicate between different routing instances with only static routing?

Hello Guilherme,

Then how we can achieve the requirement mentioned by yoon in that scenario.

Hello,

You can configure a static route with the next-table option from a VRF table to inet.0, or from inet.0 to a VRF table. However, in both cases, there's a risk of creating a routing loop.

For example, if you configure a default route (0.0.0.0/0) in a VRF pointing to inet.0, and then configure another default route in inet.0 pointing back to the VRF using next-table, this would cause a routing loop. To prevent such situations, Junos enforces loop protection and rejects the configuration.

Dear Juniper,

I am curious about the "next-table" option of "static routing".

The topology is as follows.

First, the below config is committed.
"set routing-options static route 33.33.33.0/24 next-table VRF10.inet.0"

After that, when I commit the below config, an error occurs.
"set routing-instances VRF10 routing-options static route 11.11.11.0/24 next-table inet.0"

[edit]
root@XM1# commit
error: [rib inet.0 routing-options static]
next-table may loop
error: configuration check-out failed"

I searched on the internet and it says it's because of "loop protection".

I'm curious about the conditions under which loop protection occurs (when it occurs).

And is it impossible to communicate between different routing instances with only static routing?

Go asymmetrically through a third (otherwise empty) VRF. The commit check won't bother you this way (but check yourself that you're not creating any loop, or be prepared for PFE WEDGE errors and total loss of traffic).

Hello Guilherme,

Then how we can achieve the requirement mentioned by yoon in that scenario.

Hello,

You can configure a static route with the next-table option from a VRF table to inet.0, or from inet.0 to a VRF table. However, in both cases, there's a risk of creating a routing loop.

For example, if you configure a default route (0.0.0.0/0) in a VRF pointing to inet.0, and then configure another default route in inet.0 pointing back to the VRF using next-table, this would cause a routing loop. To prevent such situations, Junos enforces loop protection and rejects the configuration.

Dear Juniper,

I am curious about the "next-table" option of "static routing".

The topology is as follows.

First, the below config is committed.
"set routing-options static route 33.33.33.0/24 next-table VRF10.inet.0"

After that, when I commit the below config, an error occurs.
"set routing-instances VRF10 routing-options static route 11.11.11.0/24 next-table inet.0"

[edit]
root@XM1# commit
error: [rib inet.0 routing-options static]
next-table may loop
error: configuration check-out failed"

I searched on the internet and it says it's because of "loop protection".

I'm curious about the conditions under which loop protection occurs (when it occurs).

And is it impossible to communicate between different routing instances with only static routing?