--- zzzz-none-000/linux-4.9.231/net/ipv4/ipconfig.c	2020-07-22 07:10:54.000000000 +0000
+++ falcon-5590-729/linux-4.9.231/net/ipv4/ipconfig.c	2022-03-30 12:03:35.000000000 +0000
@@ -455,6 +455,8 @@
 			ic_netmask = htonl(IN_CLASSB_NET);
 		else if (IN_CLASSC(ntohl(ic_myaddr)))
 			ic_netmask = htonl(IN_CLASSC_NET);
+		else if (IN_CLASSE(ntohl(ic_myaddr)))
+			ic_netmask = htonl(IN_CLASSE_NET);
 		else {
 			pr_err("IP-Config: Unable to guess netmask for address %pI4\n",
 			       &ic_myaddr);