traceroute on Mac: 15 Seconds per Silent Hop, and No -T
On the Mac mini that runs this business, traceroute 1.1.1.1 took 77.0 seconds to print 8 lines. The route itself was fine: traceroute -n -w 1 -q 1 1.1.1.1 printed the same 8 hops in 4.6 seconds. Five routers on the way don't answer traceroute's probes, and macOS waits 5 seconds for each of 3 probes on each of them, one at a time: 15 seconds per silent hop.
"traceroute mac" gets 124 Google autocomplete completions, led by "how to traceroute on mac". It's already installed. Below: four targets timed with default and fast settings on macOS 26.4.1, the Linux flags it rejects, what happens when the destination never answers, and what 15 Mac traceroute questions on Stack Exchange sites are about.
How to run traceroute on Mac
/usr/sbin/traceroute and /usr/sbin/traceroute6 ship with macOS. Both are setuid root (-r-sr-xr-x root wheel), so a normal user can run them without sudo. Running traceroute with no arguments prints Version 1.4a12+Darwin: this is the old LBL traceroute with Apple patches, not the traceroute 2.1 that Linux distributions ship.
traceroute example.com # UDP probes, 3 per hop, up to 64 hops
traceroute -n -w 1 -q 1 example.com # no reverse DNS, 1 s wait, 1 probe per hop
traceroute -I example.com # ICMP echo instead of UDP
traceroute6 2606:4700:4700::1111 # IPv6 is a separate commandThere is no GUI version left. The Network Utility app had a Traceroute tab, and Apple's macOS Catalina guide still documents it. On this machine it is not in /System/Applications/Utilities or /System/Library/CoreServices/Applications, and mdfind -name "Network Utility" returns nothing.
Why traceroute is slow on Mac
The defaults, from man traceroute on this machine: 3 probes per hop (-q), a 5-second wait for each (-w), and a maximum of net.inet.ip.ttl hops, which sysctl reports as 64. A router that doesn't reply produces * * *, and the line takes 15 seconds to finish. I ran the default command and the fast one against four targets over the Wi-Fi uplink (en1):
/usr/bin/time -p, single runs. Hops 2 and 3 (my ISP's first routers) never answer on any target.The arithmetic matches almost exactly. The 8.8.8.8 trace has 2 silent hops (30 s) and finished in 31.9 s. The 1.1.1.1 trace has 5 (75 s) and took 77.0 s. example.com had the same 2 silent hops plus one lost probe on hop 1, 35 s, and took 36.8 s. Reverse DNS isn't where the time goes: traceroute -n 8.8.8.8 took 31.3 s against 31.9 s without -n.
Linux behaves differently, which is why tutorials written there feel faster. The traceroute 2.1.6 man page gives a default of 30 hops, not 64, and a -N default of 16 probes sent simultaneously, plus an adaptive wait that stops early once nearby hops have answered. The Mac version has neither. Its only related knob is -z, a pause between probes, which defaults to zero.
When the destination never answers
192.0.2.1 is a documentation address (TEST-NET-1) that nothing on the internet answers. With the fast settings, traceroute printed 63 lines of * after my router, ran all the way to hop 64, and took 71.0 s. With the defaults it printed 63 lines of * * * and ran 968 seconds, 16 minutes and 8 seconds: 63 silent hops at 15 s each is 945. Both runs exited 0.
That exit code is the scripting trap. traceroute reports success when it finishes its loop, not when it reaches the host, so if traceroute -q1 "$host" >/dev/null; then takes the success branch for an address that never answered. It does exit non-zero for usage errors and for traceroute: unknown host. This is the same pattern as dig exiting 0 on NXDOMAIN, which I measured in nslookup on Mac.
Linux flags that fail on Mac
I ran the flags that Linux guides use, each with -n -q1 -w1 -m3 8.8.8.8:
| Command | Result on macOS 26.4.1 | Exit |
|---|---|---|
traceroute -T (TCP SYN on Linux) | usage message | 1 |
traceroute -4, -6, -U, --version | usage message | 1 |
traceroute -P tcp | traceroute: pcap_activate() failed: | 71 |
traceroute -P icmp / -I | works without sudo | 0 |
traceroute -P udp | works (the default) | 0 |
TCP mode is the one people need for firewalled paths, and it's spelled -P tcp -p 443 here. As a normal user it fails before sending anything: it wants a packet-capture device, and /dev/bpf0 on this machine is crw------- root wheel. I didn't test it with sudo (this machine has no passwordless sudo), so I can only say that it doesn't work without it. ICMP mode works because the setuid binary opens its raw socket as root. On Linux, -T is one of the built-in probe methods and -I usually needs root; here ICMP is the one that works without sudo.
There's no -6 either. IPv6 has its own command, traceroute6, and its flag set is closer to Linux: its man page lists -I for ICMP6, -T for TCP and -U for UDP, the same letters the IPv4 command rejects. On this Mac, which has only a link-local IPv6 address on Wi-Fi, traceroute6 2001:4860:4860::8888 printed connect: No route to host and stopped within 0.01 s.
UDP vs ICMP, and the VPN case
Some devices answer one probe type and not the other. Tailscale's resolver at 100.100.100.100 is a clean example. This machine is reached remotely over Tailscale (the setup is in Tailscale SSH on Mac), and route -n get 100.100.100.100 shows interface: utun5. A UDP traceroute to it printed 1 *, 2 *, 3 *. traceroute -I got 1 100.100.100.100 0.570 ms. It's one hop away and only answers ICMP.
It cuts both ways: on the 1.1.1.1 path, hop 6 answered UDP (218.145.42.210) and was * with ICMP. Run a broken-looking trace once each way before drawing conclusions.
What 15 Q&A threads are about
I pulled every Apple Stack Exchange question with "traceroute" in the title (7) and every Super User traceroute question in the API's top 100 by votes that is about a Mac (8, filtered by title and tags), through the Stack Exchange API. They split three ways:
- 6 are about the output looking wrong: rows of asterisks, a single hop, or Terminal and Network Utility disagreeing. In question 125755, Network Utility showed only asterisks and Terminal didn't, and the accepted answer is that Network Utility used ICMP and Terminal used UDP, which is the 100.100.100.100 result above. In question 448015 the asker gets all asterisks with
-P udp -p 22. The top answer pastes a trace reading "30 hops max, 60 byte packets", which is Linux output, and the next one quotes the Linux spelling-I, --icmp. - 4 are a website being unreachable, where traceroute was one diagnostic step and the answer pointed somewhere else: a PeerGuardian filter, a login item, DNS configuration, and one that was never resolved.
- 5 are other things: two about reading latency figures, blocking ICMP on a server, a VPN that
-i en0couldn't get around, and a shell prompt that turned intobogon, which the top answer blames on the ISP's DNS server answering a reverse lookup.
The accepted answer on Super User 943471, about a line that always reads 6 * * *, makes the point that matters most for the first group: a silent hop with live hops after it isn't a problem, it's a router that doesn't reply to probes. My hops 2 and 3 are like that on every target.
A faster traceroute wrapper
For scripts I use one probe, a one-second wait, 30 hops, a retry with ICMP when UDP didn't reach the host, and an exit code that means "reached":
trace() {
local hops=${2:-30} out dest last
out=$(traceroute -n -w 1 -q 1 -m $hops "$1" 2>&1) || { print -r -- "$out" >&2; return 2; }
dest=${${out%%\)*}##*\(}
last=${out##*$'\n'}
if [[ $last != *" $dest "* ]]; then
print -u2 "trace: UDP probes did not reach $dest, retrying with ICMP (-I)"
out=$(traceroute -I -n -w 1 -q 1 -m $hops "$1" 2>&1)
last=${out##*$'\n'}
fi
print -r -- "$out"
[[ $last == *" $dest "* ]]
}It's zsh. It takes the destination address from traceroute's first line and checks whether the last hop printed is that address. On this machine: 1.1.1.1 reached in 4.6 s and example.com in 2.6 s (exit 0). 100.100.100.100 took 33.4 s, because the UDP pass ran all 30 hops before the ICMP retry reached it at hop 1. trace 192.0.2.1 5 exited 1 and a misspelled hostname exited 2. For a continuously updating view, Homebrew's mtr formula combines traceroute and ping, but its caveat says it "requires root privileges so you will need to run `sudo mtr`". I didn't install it. Other Linux-to-Mac command gaps I've measured are in netstat on Mac and timeout command not found on Mac.
FAQ
How do I run a traceroute on a Mac?
Open Terminal and type traceroute example.com. The command is preinstalled at /usr/sbin/traceroute and runs without sudo. Add -n -w 1 -q 1 to skip reverse DNS, wait 1 second and send 1 probe per hop, which makes it finish many times faster. Use traceroute6 for IPv6 addresses.
Why is traceroute so slow on Mac?
macOS traceroute sends 3 probes per hop, one at a time, and waits up to 5 seconds for each, so every router that doesn't reply adds 15 seconds. It also allows up to 64 hops, against 30 on Linux. In a test on macOS 26.4.1, a trace to 1.1.1.1 with 5 silent hops took 77 seconds by default and 4.6 seconds with traceroute -n -w 1 -q 1.
Why does traceroute show only asterisks on Mac?
An asterisk means no reply arrived within the wait time for that probe. Many routers and firewalls ignore the UDP probes traceroute sends by default, so try traceroute -I to send ICMP echo instead. A few silent hops followed by hops that do answer are normal. If every hop is silent, a firewall on the Mac or the network may be blocking the probes or replies.
Update 2026-10-06: to see the probe packets themselves rather than the hops traceroute reports, the next tool is tcpdump, which on macOS needs sudo for any capture and defaults to a pktap interface rather than en0. The errors you get without root, and two Apple-only flags that misbehave on saved files, are in tcpdump on Mac.
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Method: all commands ran on 2026-10-06 between 13:31 and 13:52 KST on a Mac mini M4 (Mac16,10, macOS 26.4.1 build 25E253) as a normal user, over Wi-Fi (en1) on a Korean residential ISP, with the Tailscale app connected. Times are single runs from /usr/bin/time -p or the script's own timestamps, and will vary with the network. I didn't run anything with sudo, install mtr, or test IPv6 beyond the one failed traceroute6 call. Linux defaults come from the man7.org traceroute 2.1.6 page, not from a Linux machine. The 15 questions are the Stack Exchange API results for title "traceroute" on Apple Stack Exchange (all 7) and the Super User questions about a Mac among the top 100 by votes (8 of 100, checked by hand), classified by reading each question and its top answer on 2026-10-06. The 124 autocomplete count comes from our own Google suggest collection on the same day.