Doc update

docs/tutorials/traefik-proxy.md

@@ -138,3 +138,21 @@ Now that we have verified that ExternalDNS will automatically manage Traefik DNS
 $ kubectl delete -f traefik-ingress.yaml
 $ kubectl delete -f externaldns.yaml
 ```
+
+## Additional Flags
+
+| Flag | Description |
+| --- | --- |
+| --traefik-disable-legacy | Disable listeners on Resources under traefik.containo.us |
+| --traefik-disable-new | Disable listeners on Resources under traefik.io |
+
+### Disabling Resource Listeners
+
+Traefik has deprecated the legacy API group, traefik.containo.us, in favor of traefik.io. By default the traefik-proxy source will listen for resources under both API groups; however, this may cause timeouts with the following message
+
+```
+FATA[0060] failed to sync traefik.io/v1alpha1, Resource=ingressroutes: context deadline exceeded
+```
+
+In this case you can disable one or the other API groups with `--traefik-disable-new` or `--traefik-disable-legacy`
+