[Fedora 15] Slow network after upgrade
Hi; I run two servers at home, and I recently ran into a trickier sort of problem.
We'll call them ns1 and ns2. ns1 is the primary server where serious bizniz happens, and ns2 is a testbed for stuff.
Both servers are reasonably identical: both are AMD + Asus MB, with embedded Realtek chipset for ethernet, and with a second ethernet card (100% identical, bought at the same time etc).
Both servers have similar functions: they run bind, httpd, sendmail, mysql, php, several wikis, forums and such; ns1 also runs dovecot and squirrelmail. Both were assembled and installed by me.
On both servers, eth0 is the internal network's NIC, and it is trusted. eth1 is IP-masquerading, and not trusted; iptables pokes enough prerequisite holes to it, to let it work as web and mail server etc. Both servers have identical iptables setup. On both systems, eth1 routes traffic outside. On both systems, eth0 has a static IP (192.168.0.1 and .2, respectively), and eth1 receives its static IP address from my ISP (with MAC-based identification).
Both servers are connected to the same DSL box, and both servers are connected to the same switch in internal network, using same type of cable. Yay for standardization.
Originally, both servers ran Fedora 13.
I upgraded ns2 around January 2012 to Fedora 15, via DVD, using "upgrade" option, and everything went swimmingly, no problems. I have continued to update the server via yum, and everything is still just fine.
I upgraded ns1 on 1st of May, 2012, to Fedora 15, via DVD, using "upgrade" option, and performance is drastically different. Immediately after upgrading, I ran yum to retrieve update packets, and I thought that was that.
ns2 continues behaving splendidly.
ns1, on the other hand, slows down and then messes something between eth0 and eth1. This is detectable with a simple test: I try to download stuff when my desktop is using ns1 for routing; speed starts at 35 KB/s, then keeps dropping until it is at zero.
If I swap to ns2 for routing, and try to download again, I will get the 2 Mbit/s as I'm supposed to.
However, if I log in to ns1, and start a download off the command line (like, say, with wget), I will get 2Mbit/s again.
This stunted downloading includes downloads from the server itself, while in internal network: prior to update, it worked fast, and content was quick to load.
ethtool tells me that all NICs are running at full speed.
I have already tried to disable ipv6, up to the point of removing ip6tables from loadable services, but ns2 runs just fine with ip6tables lurking about. Both systems do not use ipv6 for any of their NICs.
I have added biosdevname=0 to kernel line in grub.conf, and it still makes no difference (and ns2 runs just fine without it).
I have tried to reinstall kernel and various other things, and none of them make a difference.
My kernel line looks like this:
kernel /vmlinuz-126.96.36.199-6.fc15.x86_64 root=UUID=9b7277da-bf2f-4ef1-be90-2f7226935c9a ro rd_MD_UUID=84894a3e:0e0dff17:4dc693b9:2565f0cc rd_MD_UUID=a4851993:0ba36d09:736988a9:b06084d4 rd_NO_LUKS rd_NO_LVM rd_NO_DM LANG=en_US.UTF-8 SYSFONT=latarcyrheb-sun16 KEYTABLE=fi-latin1 iommu=noaperture biosdevname=0
I do not spot any obvious problems in /var/log/messages, /var/log/boot.log or dmesg.
I am starting to reach my wits' end, and I can't figure it out.
Please help me. Or at least toss some ideas, so I can try to google and figure it out on my own; I'm out of ideas.
---------- Post added at 03:26 AM ---------- Previous post was at 01:00 AM ----------
Additional information and a tiny correction:
This is eth0:
Bridge: nVidia Corporation MCP61 Ethernet (rev a2)
Subsystem: ASUSTeK Computer Inc. Device 83a4
Flags: bus master, 66MHz, fast devsel, latency 0, IRQ 43
Memory at dedf9000 (32-bit, non-prefetchable) [size=4K]
I/O ports at c480 [size=8]
Capabilities:  Power Management version 2
Capabilities:  MSI: Enable+ Count=1/8 Maskable+ 64bit+
Capabilities: [6c] HyperTransport: MSI Mapping Enable- Fixed+
Kernel driver in use: forcedeth
Kernel modules: forcedeth
This is eth1:
Ethernet controller: Realtek Semiconductor Co., Ltd. RTL-8169 Gigabit Ethernet (rev 10)
Subsystem: Realtek Semiconductor Co., Ltd. RTL8169/8110 Family PCI Gigabit Ethernet NIC
Flags: bus master, 66MHz, medium devsel, latency 64, IRQ 18
I/O ports at d800 [size=256]
Memory at deeffc00 (32-bit, non-prefetchable) [size=256]
Expansion ROM at deec0000 [disabled] [size=128K]
Capabilities: [dc] Power Management version 2
Kernel driver in use: r8169
Kernel modules: r8169
Now, a quick google shows that some people have had problems with forcedeth drivers. Any idea if this would be it?
Would this get fixed by feeding Fedora 16 to it? Or should I try something else?