собственно суть проблемы в следующем: периодически перестают пинговаться ip шники находящиеся во влане. при этом если сделать clear ip arp на непингующийся адрес, то он начинает пинговаться. никакой зависимости по времени не отмечено, проблема возникает эпизодически.
sh int vl 4090
Vlan4090 is up, line protocol is up
Hardware is EtherSVI, address is 0023.eadf.2400 (bia 0023.eadf.2400)
Internet address is 172.21.6.1/24
MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive not supported
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:00, output 00:00:00, output hang never
Last clearing of "show interface" counters 00:13:51
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 3000 bits/sec, 4 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
L2 Switched: ucast: 17 pkt, 1548 bytes - mcast: 244 pkt, 16523 bytes
L3 in Switched: ucast: 2451 pkt, 167240 bytes - mcast: 0 pkt, 0 bytes mcast
L3 out Switched: ucast: 2504 pkt, 171460 bytes mcast: 0 pkt, 0 bytes
5635 packets input, 515305 bytes, 0 no buffer
Received 259 broadcasts (0 IP multicasts)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
3788 packets output, 254190 bytes, 0 underruns
0 output errors, 0 interface resets
0 output buffer failures, 0 output buffers swapped out
sh ru int vl 4090
Building configuration...
Current configuration : 1450 bytes
!
interface Vlan4090
ip address 172.21.6.1 255.255.255.0
ip access-group diagnet in
no ip redirects
end
sh ip int vl 4090
Vlan4090 is up, line protocol is up
Internet address is 172.21.6.1/24
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
Outgoing 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 never sent
ICMP unreachables are always sent
ICMP mask replies are never sent
IP fast switching is enabled
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
Probe proxy name replies are disabled
Policy routing is disabled
Network address translation is disabled
BGP Policy Mapping is disabled
Input features: Access List
Output features: IP Post Routing Processing, HW Shortcut Installation
Post encapsulation features: MTU Processing, IP Protocol Output Counter, IP Sendself Check, HW Shortcut Installation
Sampled Netflow is disabled
IP Routed Flow creation is disabled in netflow table
IP Bridged Flow creation is disabled in netflow table
WCCP Redirect outbound is disabled
WCCP Redirect inbound is disabled
WCCP Redirect exclude is disabled
IP multicast multilayer switching is disabled