2901 High CPU usage with Hyper-V Replication

[Clayton Tschirhart]

ISR: 2901 with ISM

iOS: 15.7

I have several vlans setup on my networks.  Everything is inter-vlan routed through my 2901 routers because day to day maintenance for firewall and zones is easier with the cisco configuration professional express.  For the most part, everything works great.  All the vlans in my LAN zone are able to communicate just fine-- however when I when I enable Hyper-V replication on a specific machine between 2 specific vlans between I get really high CPU usage which brings down my CME.  Both vlans are in my LAN zone.  I've included the configuration for the specific vlans-- not sure if there's anything else I should look at.

S-RT1#show ip int gigabitEthernet 0/0/0
GigabitEthernet0/0/0 is up, line protocol is up
  Internet protocol processing disabled
S-RT1#show int gigabitEthernet 0/0/0
GigabitEthernet0/0/0 is up, line protocol is up
  Hardware is EHWIC-4 Gigabit Ethernet, address is 0078.880d.2ff0 (bia 0078.880d.2ff0)
  MTU 1500 bytes, BW 1000000 Kbit/sec, DLY 10 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Full-duplex, 1000Mb/s
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:00, output never, output hang never
  Last clearing of "show interface" counters never
  Input queue: 0/75/0/500 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 1055000 bits/sec, 250 packets/sec
  5 minute output rate 2258000 bits/sec, 337 packets/sec
     178403441 packets input, 1487146880 bytes, 0 no buffer
     Received 772682 broadcasts (5372912 multicasts)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 0 multicast, 0 pause input
     0 input packets with dribble condition detected
     217440069 packets output, 3451606432 bytes, 0 underruns
     0 output errors, 0 collisions, 1 interface resets
     0 unknown protocol drops
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier, 0 pause output
     0 output buffer failures, 0 output buffers swapped out

S-RT1#show ip int vlan 290
Vlan290 is up, line protocol is up
  Internet address is 10.20.90.1/24
  Broadcast address is 255.255.255.255
  Address determined by non-volatile memory
  MTU is 1500 bytes
  Helper address is not set
  Directed broadcast forwarding is disabled
  Multicast reserved groups joined: 224.0.0.18 224.0.0.5 224.0.0.6
  Outgoing access list is not set
  Inbound  access list is not set
  Proxy ARP is enabled
  Local Proxy ARP is disabled
  Security level is default
  Split horizon is enabled
  ICMP redirects are always sent
  ICMP unreachables are always sent
  ICMP mask replies are never sent
  IP fast switching is enabled
  IP fast switching on the same interface is disabled
  IP Flow switching is disabled
  IP CEF switching is enabled
  IP CEF switching turbo vector
  IP Null turbo vector
  IP multicast fast switching is enabled
  IP multicast distributed fast switching is disabled
  IP route-cache flags are Fast, CEF
  Router Discovery is disabled
  IP output packet accounting is disabled
  IP access violation accounting is disabled
  TCP/IP header compression is disabled
  RTP/IP header compression is disabled
  Policy routing is disabled
  Network address translation is enabled, interface in domain inside
  BGP Policy Mapping is disabled
  Input features: Common Flow Table, Stateful Inspection, Input-Flexible-NetFlow, Ingress-NetFlow, Virtual Fragment Reassembly, Virtual Fragment Reassembly After IPSec Decryption, MCI Check
  Output features: NAT Inside, Common Flow Table, Stateful Inspection, CCE Post NAT Classification, Stateful IPS (CCE), Firewall (firewall component), NAT ALG proxy, Post-Ingress-NetFlow, Egress-Netflow, Post-Input-Flexible-NetFlow
  IPv4 WCCP Redirect outbound is disabled
  IPv4 WCCP Redirect inbound is disabled
  IPv4 WCCP Redirect exclude is disabled
S-RT1#

      show ip int vlan 390
Vlan390 is up, line protocol is up
  Internet address is 10.30.90.2/24
  Broadcast address is 255.255.255.255
  Address determined by non-volatile memory
  MTU is 1500 bytes
  Helper address is not set
  Directed broadcast forwarding is disabled
  Multicast reserved groups joined: 224.0.0.18 224.0.0.5 224.0.0.6
  Outgoing access list is not set
  Inbound  access list is not set
  Proxy ARP is enabled
  Local Proxy ARP is disabled
  Security level is default
  Split horizon is enabled
  ICMP redirects are always sent
  ICMP unreachables are always sent
  ICMP mask replies are never sent
  IP fast switching is enabled
  IP fast switching on the same interface is disabled
  IP Flow switching is disabled
  IP CEF switching is enabled
  IP CEF switching turbo vector
  IP Null turbo vector
  IP multicast fast switching is enabled
  IP multicast distributed fast switching is disabled
  IP route-cache flags are Fast, CEF
  Router Discovery is disabled
  IP output packet accounting is disabled
  IP access violation accounting is disabled
  TCP/IP header compression is disabled
  RTP/IP header compression is disabled
  Policy routing is disabled
  Network address translation is enabled, interface in domain inside
  BGP Policy Mapping is disabled
  Input features: Common Flow Table, Stateful Inspection, Input-Flexible-NetFlow, Ingress-NetFlow, Virtual Fragment Reassembly, Virtual Fragment Reassembly After IPSec Decryption, MCI Check
  Output features: NAT Inside, Common Flow Table, Stateful Inspection, CCE Post NAT Classification, Stateful IPS (CCE), Firewall (firewall component), NAT ALG proxy, Post-Ingress-NetFlow, Egress-Netflow, Post-Input-Flexible-NetFlow
  IPv4 WCCP Redirect outbound is disabled
  IPv4 WCCP Redirect inbound is disabled
  IPv4 WCCP Redirect exclude is disabled

[seanvaid]

I have not personally ever used Hyper-V, but couldn't this just be as simple as traffic overload?

Span some ports with and without replication enabled - check to see the difference in amount of traffic.