diff --git a/illumos-utils/src/route.rs b/illumos-utils/src/route.rs
index 2b6af9a9fd..96ce3fc65d 100644
--- a/illumos-utils/src/route.rs
+++ b/illumos-utils/src/route.rs
@@ -4,30 +4,80 @@
 
 //! Utilities for manipulating the routing tables.
 
+use crate::ipadm::Ipadm;
 use crate::zone::ROUTE;
 use crate::{execute, inner, output_to_exec_error, ExecutionError, PFEXEC};
 use libc::ESRCH;
-use std::net::Ipv6Addr;
+use std::net::{Ipv4Addr, Ipv6Addr};
 
 /// Wraps commands for interacting with routing tables.
 pub struct Route {}
 
+pub enum Gateway {
+    Ipv4(Ipv4Addr),
+    Ipv6(Ipv6Addr),
+}
+
 #[cfg_attr(any(test, feature = "testing"), mockall::automock)]
 impl Route {
     pub fn ensure_default_route_with_gateway(
-        gateway: &Ipv6Addr,
+        gateway: Gateway,
     ) -> Result<(), ExecutionError> {
+        let inet;
+        let gw;
+        match gateway {
+            Gateway::Ipv4(addr) => {
+                inet = "-inet";
+                gw = addr.to_string();
+            }
+            Gateway::Ipv6(addr) => {
+                inet = "-inet6";
+                gw = addr.to_string();
+            }
+        }
         // Add the desired route if it doesn't already exist
         let destination = "default";
         let mut cmd = std::process::Command::new(PFEXEC);
+        let cmd = cmd.args(&[ROUTE, "-n", "get", inet, destination, inet, &gw]);
+
+        let out =
+            cmd.output().map_err(|err| ExecutionError::ExecutionStart {
+                command: inner::to_string(cmd),
+                err,
+            })?;
+        match out.status.code() {
+            Some(0) => (),
+            // If the entry is not found in the table,
+            // the exit status of the command will be 3 (ESRCH).
+            // When that is the case, we'll add the route.
+            Some(ESRCH) => {
+                let mut cmd = std::process::Command::new(PFEXEC);
+                let cmd =
+                    cmd.args(&[ROUTE, "add", inet, destination, inet, &gw]);
+                execute(cmd)?;
+            }
+            Some(_) | None => return Err(output_to_exec_error(cmd, &out)),
+        };
+        Ok(())
+    }
+
+    pub fn ensure_opte_interface(
+        gateway: &Ipv4Addr,
+        iface: &Ipv4Addr,
+    ) -> Result<(), ExecutionError> {
+        let opte_ip = Ipadm::retrieve_opte_ip(iface)?;
+        // Add the desired route if it doesn't already exist
+        let mut cmd = std::process::Command::new(PFEXEC);
         let cmd = cmd.args(&[
             ROUTE,
             "-n",
             "get",
-            "-inet6",
-            destination,
-            "-inet6",
+            "-host",
             &gateway.to_string(),
+            &opte_ip.to_string(),
+            "-interface",
+            "-ifp",
+            &iface.to_string(),
         ]);
 
         let out =
@@ -45,10 +95,12 @@ impl Route {
                 let cmd = cmd.args(&[
                     ROUTE,
                     "add",
-                    "-inet6",
-                    destination,
-                    "-inet6",
+                    "-host",
                     &gateway.to_string(),
+                    &opte_ip.to_string(),
+                    "-interface",
+                    "-ifp",
+                    &iface.to_string(),
                 ]);
                 execute(cmd)?;
             }
diff --git a/zone-network-setup/src/bin/zone-networking.rs b/zone-network-setup/src/bin/zone-networking.rs
index f3d18832c5..91e27db3a3 100644
--- a/zone-network-setup/src/bin/zone-networking.rs
+++ b/zone-network-setup/src/bin/zone-networking.rs
@@ -7,7 +7,7 @@
 use anyhow::anyhow;
 use clap::{arg, command};
 use illumos_utils::ipadm::Ipadm;
-use illumos_utils::route::Route;
+use illumos_utils::route::{Gateway, Route};
 use omicron_common::cmd::fatal;
 use omicron_common::cmd::CmdError;
 use slog::info;
@@ -74,7 +74,7 @@ async fn do_run() -> Result<(), CmdError> {
         zone::current().await.expect("Could not determine local zone name");
     let datalink: &String = matches.get_one("datalink").unwrap();
     let static_addr: &Ipv6Addr = matches.get_one("static_addr").unwrap();
-    let gateway: &Ipv6Addr = matches.get_one("gateway").unwrap();
+    let gateway: Ipv6Addr = *matches.get_one("gateway").unwrap();
 
     // TODO: remove when https://github.com/oxidecomputer/stlouis/issues/435 is
     // addressed
@@ -91,7 +91,7 @@ async fn do_run() -> Result<(), CmdError> {
         .map_err(|err| CmdError::Failure(anyhow!(err)))?;
 
     info!(&log, "Ensuring there is a default route"; "gateway" => ?gateway);
-    Route::ensure_default_route_with_gateway(gateway)
+    Route::ensure_default_route_with_gateway(Gateway::Ipv6(gateway))
         .map_err(|err| CmdError::Failure(anyhow!(err)))?;
 
     info!(&log, "Populating hosts file for zone"; "zonename" => ?zonename);