Eclipse Mars m2e plugin fails to download repository index updates on startup. I run Eclipse behind a company firewall but the proxy settings work fine for "check for updates", "eclipse marketplace", and eclipse's built-in browser.

I have tried the following:

1. Deleting the cache directory `\eclipse\p2\org.eclipse.equinox.p2.repository\cache` and then refreshing the repositories. Preferences -> Install Update -> Available Software Sites => select the entry and click "Reload"
2. Adding `-Djava.net.preferIPv4Stack=true` to `-vmargs` in eclipse.ini

**Edit:** Proxy configurations are correctly set in $HOME/.m2/settings.xml  

**Edit:** Seems like a bug. So I raised a bug request with eclipse.org. You can view it [here](https://bugs.eclipse.org/bugs/show_bug.cgi?id=478735)

Due to this issue, eclipse fails to search and add dependency from maven repositories. 

Here is the error in .metadata/.log 

```
eclipse.buildId=4.5.0.I20150603-2000
java.version=1.8.0_60
java.vendor=Oracle Corporation
BootLoader constants: OS=win32, ARCH=x86_64, WS=win32, NL=en_IN
Framework arguments:  -product org.eclipse.epp.package.jee.product
Command-line arguments:  -os win32 -ws win32 -arch x86_64 -product org.eclipse.epp.package.jee.product

!ENTRY org.eclipse.m2e.logback.appender 4 0 2015-09-30 14:39:59.820
!MESSAGE Unable to update index for central|https://repo.maven.apache.org/maven2
!STACK 0
java.net.ConnectException: Connection timed out: connect
        at java.net.TwoStacksPlainSocketImpl.socketConnect(Native Method)
        at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
        at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
        at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
        at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172)
        at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
        at java.net.Socket.connect(Socket.java:589)
        at com.squareup.okhttp.internal.Platform.connectSocket(Platform.java:107)
        at com.squareup.okhttp.Connection.connect(Connection.java:156)
        at com.squareup.okhttp.Connection.connectAndSetOwner(Connection.java:175)
        at com.squareup.okhttp.OkHttpClient$1.connectAndSetOwner(OkHttpClient.java:120)
        at com.squareup.okhttp.internal.http.HttpEngine.nextConnection(HttpEngine.java:330)
        at com.squareup.okhttp.internal.http.HttpEngine.connect(HttpEngine.java:319)
        at com.squareup.okhttp.internal.http.HttpEngine.sendRequest(HttpEngine.java:241)
        at com.squareup.okhttp.Call.getResponse(Call.java:271)
        at com.squareup.okhttp.Call$ApplicationInterceptorChain.proceed(Call.java:228)
        at com.squareup.okhttp.Call.getResponseWithInterceptorChain(Call.java:199)
        at com.squareup.okhttp.Call.execute(Call.java:79)
        at io.takari.aether.okhttp.OkHttpAetherClient.execute(OkHttpAetherClient.java:154)
        at io.takari.aether.okhttp.OkHttpAetherClient.get(OkHttpAetherClient.java:100)
        at org.eclipse.m2e.core.internal.index.nexus.AetherClientResourceFetcher.retrieve(AetherClientResourceFetcher.java:79)
        at org.apache.maven.index.updater.AbstractResourceFetcher.retrieve(AbstractResourceFetcher.java:35)
        at org.apache.maven.index.updater.DefaultIndexUpdater.downloadIndexProperties(DefaultIndexUpdater.java:452)
        at org.apache.maven.index.updater.DefaultIndexUpdater.access$100(DefaultIndexUpdater.java:75)
        at org.apache.maven.index.updater.DefaultIndexUpdater$IndexAdaptor.setProperties(DefaultIndexUpdater.java:607)
        at org.apache.maven.index.updater.DefaultIndexUpdater.fetchAndUpdateIndex(DefaultIndexUpdater.java:788)
        at org.apache.maven.index.updater.DefaultIndexUpdater.fetchAndUpdateIndex(DefaultIndexUpdater.java:135)
        at org.eclipse.m2e.core.internal.index.nexus.NexusIndexManager.updateRemoteIndex(NexusIndexManager.java:1127)
        at org.eclipse.m2e.core.internal.index.nexus.NexusIndexManager.updateIndex(NexusIndexManager.java:1084)
        at org.eclipse.m2e.core.internal.index.nexus.NexusIndexManager$1.run(NexusIndexManager.java:656)
        at org.eclipse.m2e.core.internal.index.nexus.IndexUpdaterJob.run(IndexUpdaterJob.java:72)
        at org.eclipse.core.internal.jobs.Worker.run(Worker.java:55)

```