My Bitcoin full node worked in the past, but some time ago, it stopped synchronizing properly. The blockcount increases but stays far behind the blockchain:
% bitcoin-cli getblockcount
457842
(The chain is at 493006 at the same time)
bitcoin-cli getpeerinfo
shows that I have only two peers (I kept old results and, when it worked, it was several dozens of peers). Network seems OK on this machine, I can find no connectivity problem (tested with RIPE Atlas probes).
Log shows:
2017-11-04 06:58:01 UpdateTip: new best=000000000000000001605913d6d8dcf9ba337d613fc78a269f6c1ac0bc1a3e1e height=457868 version=0x20000002 log2_work=86.145812 tx=205962119 date='2017-03-18 20:33:31' progress=0.767130 cache=553.1MiB(4251353txo)
2017-11-04 06:58:58 UpdateTip: new best=000000000000000001be0ed9edf7d9bce998acf5019833624b929df320544df7 height=457869 version=0x20000002 log2_work=86.145846 tx=205963787 date='2017-03-18 20:46:52' progress=0.767136 cache=553.5MiB(4254813txo)
2017-11-04 06:59:21 UpdateTip: new best=0000000000000000024e01c470375adb787205320c094dccb5e5177b71381fab height=457870 version=0x20000002 log2_work=86.14588 tx=205965243 date='2017-03-18 20:49:17' progress=0.767141 cache=553.5MiB(4254630txo)
2017-11-04 06:59:32 UpdateTip: new best=0000000000000000017f1f8cc3a3adb4117563f4da24e0e8bf84eefc27689a87 height=457871 version=0x20000000 log2_work=86.145915 tx=205967793 date='2017-03-18 21:02:50' progress=0.767150 cache=553.8MiB(4256794txo)
2017-11-04 06:59:34 UpdateTip: new best=000000000000000000dddeee9c69bc6801414576d3d1f2f386077d72782f15f8 height=457872 version=0x20000000 log2_work=86.145949 tx=205968320 date='2017-03-18 21:07:23' progress=0.767152 cache=553.8MiB(4257262txo)
Version seems to be the latest one:
% bitcoind -version
Bitcoin Core Daemon version v0.15.0.0-g3751912e8e
Running on Ubuntu "xenial" (16.04)
-debug bench
will help you get an idea of how slow it is.