Geo routing (lines)

Geo routing lets one hostname return different answers to visitors from different places. For example, you can send visitors in Asia to an Asian server, send users of one ISP to a dedicated IP, or send your office network to an internal address. Yeap Cloud DNS calls these conditions Traffic routing.

#Kinds of lines

A record's routing line can be built from three kinds of conditions:

You can combine location and ISP, for example "China / Guangdong" plus one ISP. A record with no conditions at all is the hostname's default line. The console shows it as Global default.

How the visitor's location is determined: the nameserver looks at the IP address the query came from to work out location and ISP. If the recursive resolver sends client subnet information (EDNS Client Subnet) with the query, that subnet is used. Otherwise the resolver's own IP is used. So for visitors on a public resolver, the answer depends on whether that resolver sends client subnet information.

#Set a line on a record

1. Open the zone's records page.
2. Add the default record first. Add a record with no line, for example name www, type A, content 203.0.113.10.
3. Add a second record with the same name and type, or edit an existing one. While the row is in edit mode, click its Traffic routing cell to open the Traffic routing configuration window:
   • Geolocation: pick continent, country, province/region and city. Each level has an "All" option, which means don't narrow further.
   • ISP: pick a country and an ISP type, then search for the ISP.
   • Custom route: pick a CIDR list.
4. Click OK to close the window, then save the record.

The Traffic routing column in the record list shows each record's line. Hover over it to see the full conditions. The line filter above the list lets you show only Geolocation or Global default records.

#How matching works

For each query, the nameserver looks at the records with the same name and type and picks the set that best matches the visitor:

1. A more precise location wins: city > province/region > country > continent.
2. A record with an ISP set matches only if the visitor's ISP is the same. When it does match, it beats a record at the same location level with no ISP set.
3. A record with a custom line matches only if the visitor's IP is in that CIDR list. A record that has only a custom line (no location and no ISP) ranks at the same level as a continent match when it matches. That is below country-level and more precise location lines.
4. If no record with a line matches, the default record is returned.

For example, say www has three A records: the default 203.0.113.10, "Asia" 198.51.100.20, and "Asia / Japan" 198.51.100.30. A query from Japan gets 198.51.100.30, a query from Singapore gets 198.51.100.20, and a query from Europe gets 203.0.113.10.

#Multiple records and weights

You can have several records with the same name and type on one line, for simple load sharing:

• A / AAAA: all matching records are returned, in a random order each time. The record's Priority field acts as a weight here. A higher value makes the record more likely to come first. A blank or 0 counts as weight 1. When all records have the same weight, the order is fully random.
• CNAME: only one record is returned each time, picked at random by weight.

#Custom lines (CIDR lists)

#Create a CIDR list

1. Go to DNS → CIDR lists. The top of the page shows CIDR quota usage. The quota is the total CIDR allowance across all your DNS plans.
2. Click Add CIDR list. Enter a CIDR name such as "Office egress" and an optional description, then save.
3. In the list, click the list's entry count, "View details" View details to open its entries page.

#Add IP ranges

• Click Add entry. Enter the CIDR (for example 192.0.2.0/24 or 2001:db8::/64), an optional description, and the IP version: Auto-detect, IPv4 or IPv6. The version you pick must match the address.

• Or click Bulk import and enter one entry per line in this format:

  textCopy

  CIDR|description|IP version
  192.0.2.0/24|Office egress|ipv4
  2001:db8::/64|IPv6 test network

  You can leave out the IP version. It defaults to auto-detect.

• Select several entries and use Bulk actions to delete them or change their IP version together.

Lists marked system preset come from the platform. You can use them in records, but you can only view them, not edit them.

#Use a list in a record

In Traffic routing configuration, pick the list under Custom route. The Usage status column on the CIDR lists page shows how many records use each list.