Trouble running two NICs with intel_iommu=on on Linux?

Question

Computer networks

Hello!
1. MB - Gigabyte GA-P85-D3 rev2.0, BIOS version FD
2. Memory - Geli 2x8 1600 11-11-11.
3. Processor - Core i7 4790 3.6 GHz Scythe Tatsumi cooler.
4. Video card - Shapphire Radeon R9 270 2Gb GDDR5.
5. Chassis - Cooler Master K350 PSU Cheiftech Smart fans for intake 1 and exhaust 1.
6. HDD - OSZ Vertex 460 120 GB.
7. Network adapter Dlink D-Link DFE-520TX
8. Specify other equipment as needed (CD, DVD, CD-RW) no.
9. Operating system(s) used (if you are using a Zver-type assembly, then specify it!!!) - described below
10. Is the computer overclocked? No
11. Was the computer stable? If so, what changed in the computer configuration, in the BIOS settings, in the operating system, after which the computer began to work unstably.
12. Bought 15 shi pcs a week ago. Those. all the equipment is new, the same, on all the same error. The task was to work simultaneously with two network adapters with two different networks. There were no problems when running Win 7 x64. But I need Linux.
Main Linux Altlinux Centaurus 7.0.5 (tried Debian 7.7, Centos 7, OpenSuSe 13.1 for fun, same error). All x64 systems
The PC has two network adapters installed. One integrated - the second discrete D-Link DFE-520TX. The system detects both.

03:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 06)
   Subsystem: Gigabyte Technology Co., Ltd Motherboard
   Kernel driver in use: r8169
04:00.0 PCI bridge: Intel Corporation 82801 PCI Bridge (rev 41)
05:03.0 Ethernet controller: VIA Technologies, Inc. VT6105/VT6106S [Rhine-III] (rev 8b)
   Subsystem: D-Link System Inc DFE-520TX Fast Ethernet PCI Adapter
        Kernel driver in use: via-rhine

The integrated network adapter goes to the switch with a 10.0.0.0 network and the Internet (what equipment at that end is not important)
The discrete one must go to the switch with the 192.168.0.0 network BUT as soon as I connect a switch or router to the second network, the PC freezes.
I change the settings in places, I change the connection order (first connect to one, then to the other) hangs
Change Dlink to 3com hangs
I put two networks turning off the integrated one - hangs

Oct 29 09:36:45 104-9 kernel: [  153.375198] DMAR:[fault reason 02] Present bit in context entry is clear
Oct 29 09:36:45 104-9 kernel: [  153.375202] dmar: DRHD: handling fault status reg 3
Oct 29 09:36:45 104-9 kernel: [  153.375203] dmar: DMAR:[DMA Read] Request device [05:00.0] fault addr 2000 
Oct 29 09:36:45 104-9 kernel: [  153.375203] DMAR:[fault reason 02] Present bit in context entry is clear
Oct 29 09:36:45 104-9 kernel: [  153.375207] dmar: DRHD: handling fault status reg 2
Oct 29 09:36:45 104-9 kernel: [  153.375209] dmar: DMAR:[DMA Read] Request device [05:00.0] fault addr 2000 
Oct 29 09:36:45 104-9 kernel: [  153.375209] DMAR:[fault reason 02] Present bit in context entry is clear
Oct 29 09:36:45 104-9 kernel: [  153.375214] dmar: DRHD: handling fault status reg 2
Oct 29 09:36:45 104-9 kernel: [  153.375216] dmar: DMAR:[DMA Read] Request device [05:00.0] fault addr 2000 
Oct 29 09:36:45 104-9 kernel: [  153.375216] DMAR:[fault reason 02] Present bit in context entry is clear

turn off one of the networks, boot - everything is fine! The log is clean. Setevka both obviously working. I tried not to install Dlink but 3com network network, the same trouble ...
lspci

00:14.0 USB controller: Intel Corporation 8 Series/C220 Series Chipset Family USB xHCI (rev 05)
00:16.0 Communication controller: Intel Corporation 8 Series/C220 Series Chipset Family MEI Controller #1 (rev 04)
00:16.3 Serial controller: Intel Corporation 8 Series/C220 Series Chipset Family KT Controller (rev 04)
00:1a.0 USB controller: Intel Corporation 8 Series/C220 Series Chipset Family USB EHCI #2 (rev 05)
00:1b.0 Audio device: Intel Corporation 8 Series/C220 Series Chipset High Definition Audio Controller (rev 05)
00:1c.0 PCI bridge: Intel Corporation 8 Series/C220 Series Chipset Family PCI Express Root Port #1 (rev d5)
00:1c.2 PCI bridge: Intel Corporation 8 Series/C220 Series Chipset Family PCI Express Root Port #3 (rev d5)
00:1c.3 PCI bridge: Intel Corporation 82801 PCI Bridge (rev d5)
00:1d.0 USB controller: Intel Corporation 8 Series/C220 Series Chipset Family USB EHCI #1 (rev 05)
00:1f.0 ISA bridge: Intel Corporation B85 Express LPC Controller (rev 05)
00:1f.2 SATA controller: Intel Corporation 8 Series/C220 Series Chipset Family 6-port SATA Controller 1 [AHCI mode] (rev 05)
00:1f.3 SMBus: Intel Corporation 8 Series/C220 Series Chipset Family SMBus Controller (rev 05)
01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Curacao PRO [Radeon R9 270]
01:00.1 Audio device: Advanced Micro Devices, Inc. [AMD/ATI] Cape Verde/Pitcairn HDMI Audio [Radeon HD 7700/7800 Series]
03:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 06)
04:00.0 PCI bridge: Intel Corporation 82801 PCI Bridge (rev 41)
05:03.0 Ethernet controller: VIA Technologies, Inc. VT6105/VT6106S [Rhine-III] (rev 8b)

those. there is no device 05:00.0 at all
The problem is somehow solved if you disable intel_iommu=off when loading the kernel, but I need virtualization to forward network adapters to virtual machines.
on the altlinux forum they are actively helping forum.altlinux.org/index.php/topic,33381.0.html , but I still have not found a solution to my problem. I ask for help in setting up the system.