High ping and low speed over twisted pair cable from PC(Ubuntu) to router. What could be the problem?

Question

ubuntu

Router - TP-LINK WR841N
Internet - 100 MB
"mtr host" shows that the losses start already from the first point - 192.168.0.1 (router address)
OS- Ubuntu 15.04
On Windows, the problem is not reproduced (the second system is on the stationary)
Standard gigabit network card does not work (mother - Asus P8H67. Built-in - Realtek's card is not the only one from the systems, in principle, the orange LED on it is constantly on). I'm using a Realtech 100Mb PCI card. The WiFi devices work fine too.
The first 10 minutes the network works perfectly.
ifconfig
eth0 Link encap:Ethernet HWaddr 00:a1:b0:11:ca:d8
inet addr:192.168.0.101 Bcast:192.168.0.255 Mask:255.255.255.0
inet6 addr: fe80::2a1:b0ff:fe11:cad8/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:9921 errors:0 dropped:92 overruns:0 frame:0
TX packets:8883 errors: 0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:8152490 (8.1 MB) TX bytes:1603069 (1.6 MB)
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:876 errors:0 dropped:0 overruns:0 frame:0
TX packets:876 errors:0 dropped:0 overruns:0 carrier: 0
collisions:0 txqueuelen:0
RX bytes:89994 (89.9 KB) TX bytes:89994 (89.9 KB)
The problem still remains. The maximum MTU that I can set is 1500. In the router settings, it also costs 1500, but then, as I understand it, then - to the world.

Answer 1

Dig in the direction of the mtu settings on the network card, in ubunt. Your situation resembles an incorrect mtu configuration and, as a result, excessive fragmentation of packets and overflow of the network card buffer. As a result, such problems begin.