Add FAQ about cali interface MAC

projectcalico · Nov 22, 2017 · 9750b65 · 9750b65
1 parent 5afabfe
commit 9750b65
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diff --git a/master/usage/troubleshooting/faq.md b/master/usage/troubleshooting/faq.md
@@ -49,6 +49,13 @@ interface.  This makes the host behave like a gateway, responding to
 ARPs for 169.254.1.1 without having to actually allocate the IP address
 to the interface.
 
+## Why do all cali\* interfaces have the MAC address ee:ee:ee:ee:ee:ee?
+
+In some setups the kernel is unable to generate a persistent MAC address so
+setting one avoids that problem. Since traffic over those interfaces does not
+reach the Data link layer the MAC Address is never used and can therefore be
+the same for all the cali\* interfaces.
+
 ## Can I prevent my Kubernetes pods from initiating outgoing connections?
 
 Yes! The Kubernetes [`NetworkPolicy`](https://kubernetes.io/docs/concepts/services-networking/network-policies/)