Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

What are IP-addresses, subnets, URIs Firefox Sync uses?

  • 4 replies
  • 2 have this problem
  • 237 views
  • Last reply by cor-el

more options

What is complete list of IPs, subnets and/or URIs Firefox Sync needs access to to work correctly?

I need this because I live in Russia and our Internet regulator RosKomNadzor blocked some of these (at least 18.236.108.89) so Firefox Sync is not really working most of the time and I want to petition them to whitelist Firefox service networks.

Also I am pretty sure information about Firefox service addresses will be useful for other users such as network admins (enterprise proxy configuration, firewall settings, etc).

Chosen solution

There are lots of mirror servers used for load balancing, so I don't think it will be easy to get the full IP range.


You can toggle this pref temporarily to true to get a Sync log in case of success to test this.

  • services.sync.log.appender.file.logOnSuccess = true

Do not forget to reset services.sync.log.appender.file.logOnSuccess after you are done testing.

You can open the about:config page via the location/address bar. You can accept the warning and click "I accept the risk!" to continue.

Read this answer in context 👍 0

All Replies (4)

more options

Hi, we would not know this as work on the Firefox browser and are Volunteer Support. All sync matters we have a few trouble shooting things we can try before handing off for you to contact others for help.

Would not know who has that information.

This would be a good place to find out what is going on in your language : https://mozilla-russia.org

more options

Pkshadow, thanks for reply but I already identified the problem by checking sync logs - it definitely stumbles on this address not accessible so not much to do here.

I am hoping if someone knows list of IPs/URIs Firefox Sync uses - sometimes these are published somewhere deep in technical docs for sysadmins/devs so they can make firewall polices, etc.

As for Mozilla Russia I hear they ban on sight for such questions and can't blame them really given the recent Internet regulation practices here.

more options

You will get some idea if look at your sync logs by Copy/Paste about:sync-log into the location bar and enter.

more options

Chosen Solution

There are lots of mirror servers used for load balancing, so I don't think it will be easy to get the full IP range.


You can toggle this pref temporarily to true to get a Sync log in case of success to test this.

  • services.sync.log.appender.file.logOnSuccess = true

Do not forget to reset services.sync.log.appender.file.logOnSuccess after you are done testing.

You can open the about:config page via the location/address bar. You can accept the warning and click "I accept the risk!" to continue.