docs: update deploying-cilium.md

Adding note about this issue: #9200 (comment)

Signed-off-by: Tine Jozelj <tine@tjo.space>
Signed-off-by: Andrey Smirnov <andrey.smirnov@siderolabs.com>

Author: mentos1386

website/content/v1.8/kubernetes-guides/network/deploying-cilium.md

@@ -389,6 +389,11 @@ The above can be combined exchanged with for example Method 3 to host arbitrary
 - There are some gotchas when using Talos and Cilium on the Google cloud platform when using internal load balancers.
 For more details: [GCP ILB support / support scope local routes to be configured](https://github.com/siderolabs/talos/issues/4109)
 
+- When using Talos `forwardKubeDNSToHost=true` option (which is enabled by default) in combination with cilium `bpf.masquerade=true`.
+There is a known issue that causes `CoreDNS` to not work correctly.
+As a workaround, configuring `forwardKubeDNSToHost=false` resolves the issue.
+For more details see [the discusssion here](https://github.com/siderolabs/talos/pull/9200)
+
 ## Other things to know
 
 - After installing Cilium, `cilium connectivity test` might hang and/or fail with errors similar to

website/content/v1.9/kubernetes-guides/network/deploying-cilium.md

@@ -389,6 +389,11 @@ The above can be combined exchanged with for example Method 3 to host arbitrary
 - There are some gotchas when using Talos and Cilium on the Google cloud platform when using internal load balancers.
 For more details: [GCP ILB support / support scope local routes to be configured](https://github.com/siderolabs/talos/issues/4109)
 
+- When using Talos `forwardKubeDNSToHost=true` option (which is enabled by default) in combination with cilium `bpf.masquerade=true`.
+There is a known issue that causes `CoreDNS` to not work correctly.
+As a workaround, configuring `forwardKubeDNSToHost=false` resolves the issue.
+For more details see [the discusssion here](https://github.com/siderolabs/talos/pull/9200)
+
 ## Other things to know
 
 - After installing Cilium, `cilium connectivity test` might hang and/or fail with errors similar to