diff --git a/include/linux/siphash.h b/include/linux/siphash.h
index feeb29cd113..c8c7ae2e687 100644
--- a/include/linux/siphash.h
+++ b/include/linux/siphash.h
@@ -19,6 +19,11 @@ typedef struct {
 	u64 key[2];
 } siphash_key_t;
 
+static inline bool siphash_key_is_zero(const siphash_key_t *key)
+{
+	return !(key->key[0] | key->key[1]);
+}
+
 u64 __siphash_aligned(const void *data, size_t len, const siphash_key_t *key);
 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
 u64 __siphash_unaligned(const void *data, size_t len, const siphash_key_t *key);
diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h
index adbe8c6e20d..d39cf0e462c 100644
--- a/include/net/netns/ipv4.h
+++ b/include/net/netns/ipv4.h
@@ -6,6 +6,7 @@
 #define __NETNS_IPV4_H__
 
 #include <net/inet_frag.h>
+#include <linux/siphash.h>
 
 struct ctl_table_header;
 struct ipv4_devconf;
@@ -68,5 +69,6 @@ struct netns_ipv4 {
 	struct fib_rules_ops	*mr_rules_ops;
 #endif
 #endif
+	siphash_key_t	ip_id_key;
 };
 #endif
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 7469398264c..3e65a4e5fda 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1400,19 +1400,17 @@ EXPORT_SYMBOL(ip_idents_reserve);
 
 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs)
 {
-	static u32 ip_idents_hashrnd __read_mostly;
-	static bool hashrnd_initialized = false;
 	u32 hash, id;
 
-	if (unlikely(!hashrnd_initialized)) {
-		hashrnd_initialized = true;
-		get_random_bytes(&ip_idents_hashrnd, sizeof(ip_idents_hashrnd));
-	}
+	/* Note the following code is not safe, but this is okay. */
+	if (unlikely(siphash_key_is_zero(&net->ipv4.ip_id_key)))
+		get_random_bytes(&net->ipv4.ip_id_key,
+				 sizeof(net->ipv4.ip_id_key));
 
-	hash = jhash_3words((__force u32)iph->daddr,
+	hash = siphash_3u32((__force u32)iph->daddr,
 			    (__force u32)iph->saddr,
-			    iph->protocol ^ net_hash_mix(net),
-			    ip_idents_hashrnd);
+			    iph->protocol,
+			    &net->ipv4.ip_id_key);
 	id = ip_idents_reserve(hash, segs);
 	iph->id = htons(id);
 }
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 4935e94a2b4..d235ba87374 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -604,17 +604,21 @@ int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr)
 
 void ipv6_select_ident(struct net *net, struct frag_hdr *fhdr, struct rt6_info *rt)
 {
-	static u32 ip6_idents_hashrnd __read_mostly;
-	static bool hashrnd_initialized = false;
+	const struct {
+		struct in6_addr dst;
+		struct in6_addr src;
+	} __aligned(SIPHASH_ALIGNMENT) combined = {
+		.dst = rt->rt6i_dst.addr,
+		.src = rt->rt6i_src.addr,
+	};
 	u32 hash, id;
 
-	if (unlikely(!hashrnd_initialized)) {
-		hashrnd_initialized = true;
-		get_random_bytes(&ip6_idents_hashrnd, sizeof(ip6_idents_hashrnd));
-	}
-	hash = __ipv6_addr_jhash(&rt->rt6i_dst.addr, ip6_idents_hashrnd);
-	hash = __ipv6_addr_jhash(&rt->rt6i_src.addr, hash);
-	hash ^= net_hash_mix(net);
+	/* Note the following code is not safe, but this is okay. */
+	if (unlikely(siphash_key_is_zero(&net->ipv4.ip_id_key)))
+		get_random_bytes(&net->ipv4.ip_id_key,
+				 sizeof(net->ipv4.ip_id_key));
+
+	hash = siphash(&combined, sizeof(combined), &net->ipv4.ip_id_key);
 
 	id = ip_idents_reserve(hash, 1);
 	fhdr->identification = htonl(id);
diff --git a/net/ipv6/output_core.c b/net/ipv6/output_core.c
index 59c0b566155..9ef2522618f 100644
--- a/net/ipv6/output_core.c
+++ b/net/ipv6/output_core.c
@@ -11,8 +11,6 @@
  */
 void ipv6_proxy_select_ident(struct net *net, struct sk_buff *skb)
 {
-	static u32 ip6_proxy_idents_hashrnd __read_mostly;
-	static bool hashrnd_initialized = false;
 	struct in6_addr buf[2];
 	struct in6_addr *addrs;
 	u32 hash, id;
@@ -21,19 +19,25 @@ void ipv6_proxy_select_ident(struct net *net, struct sk_buff *skb)
 				   skb_network_offset(skb) +
 				   offsetof(struct ipv6hdr, saddr),
 				   sizeof(buf), buf);
-	if (!addrs)
-		return;
+	if (addrs)
+	{
+		const struct {
+			struct in6_addr dst;
+			struct in6_addr src;
+		} __aligned(SIPHASH_ALIGNMENT) combined = {
+			.dst = addrs[1],
+			.src = addrs[0],
+		};
 
-	if (unlikely(!hashrnd_initialized)) {
-		hashrnd_initialized = true;
-		get_random_bytes(&ip6_proxy_idents_hashrnd,
-				 sizeof(ip6_proxy_idents_hashrnd));
+		/* Note the following code is not safe, but this is okay. */
+		if (unlikely(siphash_key_is_zero(&net->ipv4.ip_id_key)))
+			get_random_bytes(&net->ipv4.ip_id_key,
+					 sizeof(net->ipv4.ip_id_key));
+
+		hash = siphash(&combined, sizeof(combined), &net->ipv4.ip_id_key);
+
+		id = ip_idents_reserve(hash, 1);
+		skb_shinfo(skb)->ip6_frag_id = htonl(id);
 	}
-	hash = __ipv6_addr_jhash(&addrs[1], ip6_proxy_idents_hashrnd);
-	hash = __ipv6_addr_jhash(&addrs[0], hash);
-	hash ^= net_hash_mix(net);
-
-	id = ip_idents_reserve(hash, 1);
-	skb_shinfo(skb)->ip6_frag_id = htonl(id);
 }
 EXPORT_SYMBOL_GPL(ipv6_proxy_select_ident);