Abstract:
List of preferences that affect networking behavior.
Description of acceptable values and behavior.
Audience:
QA testers, developers and "power users" with extensive networking internals experience.
For general technical documentation on preferences (including how to edit them), see "A Brief Guide to Mozilla Preferences"
Feedback:
and comments to bug 198252.
The sections are in roughly alphabetical + functional order.
The preferences are in order of usage by the UI (which is not often alphabetical order).
Relevant bugs are provided only when absolutely necessary.
NOTE: Do not change any of these via about:config unless you know what you are doing. If you are uncertain what that phrase means, you probably do not.
If you qualify, you are probably one or more of the following:
HTTP (this section under construction)
Preference Name | Acceptable Values | Preferences UI (in bold) and comments |
general.useragent.contentlocale |
string |
|
general.useragent.misc |
(major version number) string |
|
general.useragent.security |
string |
|
network.http.accept-encoding |
gzip,deflate (default string) |
no UI |
network.http.accept.default | text/xml,application/xml, application/xhtml+xml,text/html; q=0.9,text/plain; q=0.8,video/x-mng,image/png, image/jpeg,image/gif; q=0.2,*/*;q=0.1 |
|
network.http.default-socket-type | (empty) default |
? |
network.http.keep-alive | true (default) |
|
network.http.keep-alive.timeout | 30 |
no UI |
network.http.max-connections | 24 |
|
network.http.max-connections-per-server | 8 |
|
network.http.max-persistent-connections-per-proxy | 4 |
|
network.http.max-persistent-connections-per-server |
2 |
|
network.http.pipelining | false | ? (on in mozilla, greyed) |
network.http.pipelining.firstrequest | false |
|
network.http.pipelining.maxrequests |
4 |
|
network.http.proxy.keep-alive | true (default) |
|
network.http.proxy.pipelining | false |
? (on in mozilla, greyed) |
network.http.proxy.version | 1.1 (default) 1.0 |
|
network.http.redirection-limit |
20 |
|
network.http.request.max-start-delay |
10 |
|
network.http.sendRefererHeader |
2 |
|
network.http.sendSecureXSiteReferrer |
true |
|
network.http.use-cache |
true |
|
network.http.version |
1.1 (default) 1.0 |
File
Preference Name | Acceptable Values |
Preferences UI and comments |
security.checkloaduri | true (default) false |
No UI checkloaduri will disable file:// URLs on pages from a network (http: https: ftp:) source, for security reasons. Errors are sent to the javascript console, not to the user via dialog box. This preference only works in Gecko versions before 1.8 (so Firefox 1.0 and Mozilla Suite builds). In Firefox 1.5 and Seamonkey 1.0 this preference no longer has an effect. |
FTP (see also Proxy)
Preference Name | Acceptable Values | Preferences UI (in bold) and comments |
advanced.mailftp | false (default) true |
Preferences | Advanced | "[x] Set this email address as anonymous FTP password:" If false, FTP uses "mozilla@example.com" as anonymous FTP password (bug 101027) If true, FTP uses contents of network.ftp.anonymous_password for anonymous FTP password (bug 57763) |
network.ftp.anonymous_password | empty (default) any text string |
Preferences | Advanced | (under "[ ] Set this email address as anonymous FTP password:") [text field] If empty, FTP uses "mozilla@example.com" as anonymous FTP password. |
network.ftp.idleConnectionTimeout |
300 (default) any integer |
No UI Measured in seconds The open connection can prevent other FTP clients on your system from connecting to sites that allow only one control connection (bug 117875) |
network.dir.format |
0 = HTML view 1 = raw view 2 = HTML view 3 = XUL view |
Preferences | Debug | Networking Networking Directory Listing Format ( ) HTML ( ) XUL (tree-based) |
Cache
Preference Name | Acceptable Values | Preferences UI (in bold) and comments |
browser.cache.disk.capacity |
51200 (default) |
Preferences | Advanced | Cache Cache: [MB] MB Stored as KB |
browser.cache.disk.parent_directory |
path to Cache
folder in profile (default) |
Cache
Folder: [text box] Note: the contents of disk and mem cache are different (a very large mem cache is not the same as pointing disk cache to memory mapped disk space (RAM disk). |
browser.cache.check_doc_frequency |
1 = Every time I view the page 0 = Once per session 3 = When the page is out of date (default) 2 = Never |
Compare
the page in cache to the page on the network: |
browser.cache.disk.enable |
true (default) |
Preferences
| Debug | Cache [x] Enable Disk Cache [x] Enable Memory Cache Disabling disk cache has the effect of setting it to zero. |
browser.cache.memory.enable |
true (default) |
|
browser.cache.memory.capacity | any integer (in
KB) |
Replaced by automatic sizing in
Mozilla 1.4b (bug 105344). This value overrides the application. 0 disables feature (before, 4096K = default) |
network.http.use-cache | true (default) |
no UI |
browser.cache.disk_cache_ssl |
false (default) |
no UI, added in 1.6a (see bug 205921) |
network.prefetch-next |
true (default) |
Preferences | Advanced | Cache: Link Prefetching [x] Prefetch web pages when idle, so that links in web page designed for prefetching can load faster. |
DNS
Preference Name | Acceptable Values | Preferences UI (in bold) and comments |
network.dnsCacheExpiration |
60 (seconds) |
default pref-less, not visible in about:config. Create and set both values to "0" to disable. |
network.dnsCacheEntries |
20 (entries) |
Cookies
Please see: http://www.mozilla.org/projects/netlib/cookies/cookie-prefs.html
The old section in this document was removed because of dwitte's cookies re-write.
Proxy
Preference Name | Acceptable Values | Preferences UI (in bold) and comments |
network.proxy.type | 0 = direct 1 = manual 2 = PAC 3 -> mapped to 0 4 = WPAD |
Preferences | Advanced | Proxies Configure Proxies to Access the Internet ( ) Direct connection to the internet ( ) Auto-detect proxy settings (new in 1.8): ( ) Manual proxy configuration ( ) Automatic proxy configuration URL 3 was old Communicator value for DIRECT. |
network.proxy.http | <Protocol>
Proxy: hostname or IPv4 is acceptable. IPv6 needs to be tested. Port: 0 will cause server:port preference for that manual proxy type to be ignored. 1-65xxx is valid range |
Affects http: URLs |
network.proxy.http_port | ||
network.proxy.ssl | Affects https: URLs Possibly affects SIMAP and SNEWS |
|
network.proxy.ssl_port | ||
network.proxy.ftp | Affects ftp: URLs |
|
network.proxy.ftp_port | ||
network.proxy.gopher | Affects gopher: URLs |
|
network.proxy.gopher_port |
||
network.proxy.socks | Used
when application-specific proxy is not configured. Possibly affects other protocols |
|
network.proxy.socks_port | ||
network.proxy.socks_version |
5
(default) 4 |
Communicator supported only
SOCKS V4. |
network.proxy.no_proxies_on | localhost,
127.0.0.1 (default) string of comma delimited fqdn's, hostnames, IPv4 addresses and CDIR blocks. See "No Proxy For". |
Localhost is not proxied by default, bug 31510. |
network.proxy.autoconfig_url | empty (default) URL string |
must be absolute URl, no hostname |
Online
network.online |
true = Mozilla is online (default) false = Mozilla is offline |
Necko updates the offline|online status to this value. Changing this value does not change the actual networking status. Value is not updated if "Ask me for online state at startup" was selected for the current profile (bug 229677). |
offline.startup_state |
0 = use network.online (default) 1 = prompt user |
Preferences: Mail & Newsgroups | Offline | When starting up: (Pref affects all modules, but was moved from Pref root, bug 202529) [x] Remember previous online state (Uses network.online to set online|offline status at startup) [ ] Ask me for online state at startup (Unlike Communicator, prompt always appears, bug 239564) |
Gopher (see also Proxy)
Name | values |
Comments (bold for areas that
user configures) |
network.dir.format |
see FTP |
Unsupported
Name | values |
Comments (bold for areas that
user configures) |
browser.xul.error.pages.enabled |
false
(default) true |
Does not appear in about.config unless added explicitly. See bug 28586) |
network.protocol-handler.external.SCHEME |
false
(default) true |
Mac+Windows: sends URLs of
<SCHEME> to the default OS handler Linux/UNIX: sends URLs to application For example: network.protocol-handler.external.mailto==true is used by Phoenix/Firebird/Firefox to access default mailers. Handlers loaded before prefs are read cannot be redirected (e.g. file:) |
Obsolete/Removed (this is list is incomplete)
browser.cache.enableUnder Investigation:
browser.cache.disk.directory
networking.proxy.wais
networking.proxy.wais_port
network.http.connect.timeout
network.http.proxy.ssl.connect
offline.startup_state