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Highlighted
Beginner

Is this to much broadcast?

Hi,

can you please take a look and the interface counters:

Vlan2 is up, line protocol is up
  Hardware is EtherSVI, address is 00d0.0311.bc0a (bia 00d0.0311.bc0a)
  Description: XXXXXXXXXXXXxxxxx
  Internet address is 10.10.0.1/16
  MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
     reliability 255/255, txload 81/255, rxload 21/255
  Encapsulation ARPA, loopback not set
  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 00:13:12
  Input queue: 0/75/66505/905 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 83523000 bits/sec, 31405 packets/sec
  5 minute output rate 318748000 bits/sec, 40129 packets/sec
  L2 Switched: ucast: 4257959 pkt, 523558331 bytes - mcast: 168681 pkt, 16311106 bytes
  L3 in Switched: ucast: 23465567 pkt, 7876154325 bytes - mcast: 0 pkt, 0 bytes mcast
  L3 out Switched: ucast: 30186592 pkt, 30574459275 bytes
     24096816 packets input, 7934255792 bytes, 0 no buffer
    Received 89844 broadcasts (3 IP multicast)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     31198482 packets output, 31009106292 bytes, 0 underruns
     0 output errors, 0 interface resets
     0 output buffer failures, 0 output buffers swapped out

It is a 6509 with Sup2 and there are a few thousand of users.

On this interface are 45 subnets (secondary ip addresses) for the users, please don't ask

It is a Cable ISP with DOCSIS 2.0 and 10 CMTS (Arris). The gateway for the users are not the CMTSs, it is the 6509 Sup2.

I think that there is to much broadcast traffic and the Switch is overloaded (40% cpu usage) and the switch is doing only ip forwarding with one

default route to the other ISP. There are no ACLs or full routing table.

The problem is that the switch is droping to much packets.

With NBAR enable the CPU usage jumps to 99%.

Mod Ports Card Type                              Model              Serial No.

--- ----- -------------------------------------- ------------------ -----------

  1    2  Catalyst 6000 supervisor 2 (Active)    WS-X6K-SUP2-2GE   

  2    2  Catalyst 6000 supervisor 2 (Standby)   WS-X6K-SUP2-2GE  

  3   16  16 port 1000mb GBIC ethernet           WS-X6416-GBIC    

  4   16  16 port 1000mb GBIC ethernet           WS-X6416-GBIC    

  5   48  SFM-capable 48 port 10/100/1000mb RJ45 WS-X6548-GE-TX    

  6   48  SFM-capable 48 port 10/100/1000mb RJ45 WS-X6548-GE-TX    

  7   48  48 port 10/100 mb RJ45                 WS-X6348-RJ-45    

  8   48  48 port 10/100 mb RJ45                 WS-X6348-RJ-45    

Mod MAC addresses                       Hw    Fw           Sw           Status

--- ---------------------------------- ------ ------------ ------------ -------

  1  0001.6415.365a to 0001.6415.365b   2.2   7.1(1)       12.1(27b)E3  Ok

  2  0001.6463.7124 to 0001.6463.7125   2.2   7.1(1)       12.1(27b)E3  Ok

  3  0008.207f.3904 to 0008.207f.3913   2.2   5.4(2)       8.5(0.23)COS Ok

  4  0030.19d8.db74 to 0030.19d8.db83   1.1   5.3(1)       8.5(0.23)COS Ok

  5  0003.3232.c7c0 to 0003.3232.c7ef  10.1   7.2(1)       8.5(0.23)COS Ok

  6  000e.8491.c470 to 000e.8491.c49f   7.0   7.2(1)       8.5(0.23)COS Ok

  7  0001.9716.15c0 to 0001.9716.15ef   1.1   5.3(1)       8.5(0.23)COS Ok

  8  0001.9716.1290 to 0001.9716.12bf   1.1   5.3(1)       8.5(0.23)COS Ok

Mod Sub-Module                  Model           Serial           Hw     Status

--- --------------------------- --------------- --------------- ------- -------

  1 Policy Feature Card 2       WS-F6K-PFC2         2.0    Ok

  1 Cat6k MSFC 2 daughterboard  WS-F6K-MSFC2        1.2    Ok

  2 Policy Feature Card 2       WS-F6K-PFC2          2.0    Ok

  2 Cat6k MSFC 2 daughterboard  WS-F6K-MSFC2          1.2    Ok

2 REPLIES 2
Highlighted
Engager

A quick calculation shows you get about 113 broadcasts/s. This may seem a lot but when compared to the number of packets per sec, the b'cast level is only 0,36% of your total traffic. This is a fairly acceptable figure. Most of this is probably arp traffic. With thousands of users and an arp-aging time of three or five minutes (have to check) on Windows, you can expect such levels.

regards,

Leo

Highlighted

Do you have an idea why the switch is droping packets?

Even when I ping the switch locally, I get packet loss with a normal windows ICMP.

When I ping the swtich on 4AM, the ICMP reply is normal.

So the switch is definitely overloaded.

On a previous discussion I was told to make a SPAN port, but I am right know not able to do that because I am not at the location.