FIELD NOTE · TRACEROUTE
Find the hop
that is actually slow.
When a site is slow but the rest of the internet is fine, the bottleneck is one specific router somewhere between your Mac and them. Traceroute walks the path live, hop by hop, and puts a "slow jump" badge on the one hop most likely to be the real cause.
Each row is one router; latency is per-hop, not cumulative.
How to read the list
Each row is one router (a "hop") between your Mac and the destination. Columns: hop number, IP, hostname (if reverse-DNS resolves), ASN / ISP for that hop, and three latency samples. The latency is round-trip from your Mac to that hop, not cumulative; a slow hop in the middle does not necessarily mean the rest of the path is slow too.
The slow-jump badge
Total latency rises along the path: each hop adds a few ms. A "slow jump" is when one hop adds a lot more latency than its neighbours, e.g. hop 3 adds 4 ms, hop 4 adds 60 ms, hop 5 adds 4 ms again. That hop is the suspect: an over-utilised link, a routing detour, or a misconfigured peer. Traceroute marks it so you do not have to do the math by eye.
Three patterns to recognise
- Slow jump on hop 1 or 2. The problem is on your side: the Wi-Fi link or the local router. Open Wi-Fi Scanner.
- Slow jump in the middle, inside your ISP. ISP backbone congestion or a peering issue. Open Connection Log; if drops correlate, your ISP is the right escalation target.
- Slow jump near the destination. The site itself or its CDN is slow. Nothing you can fix on this side.
Stars (timeouts) are usually fine
A row with * * * means that hop did not answer. Many routers are configured not to respond to traceroute probes, even though traffic still passes through them. A single starred hop in the middle of an otherwise normal trace is not a problem; treat it as "this router is shy".
Pairs with Latency History and ISP Report
Use Latency History to confirm the bad hop is happening now and not just a one-off. Use ISP Report to see whose ASN that suspect hop belongs to. Together, the three turn "the internet is slow" into "this hop, this ASN, this minute".
Where to find it in the app
Click the menu-bar icon, scroll to Insights. Traceroute is in the middle row of the workspace. Type a hostname or IP, hit Return; the list builds live. Click any hop to copy its details.
TL;DR
Traceroute walks the path. The slow-jump badge picks the suspect. Read the position of the badge to know whether the problem is yours, your ISP's, or theirs.