I have a Cisco 2960-X switch and a Cisco SG-300 switch. I created VLANs on 2960-X switch (e.g. VLAN 10 with ports 1-5 and VLAN 20 with ports 6-10) and allow DHCP for each VLAN.

Now, laptop and laptop can ping each other successfully.

After this:

  1. I connect SG-300 into a port of VLAN 20. VLAN 20 assigns it an IP address by DHCP.
  2. I connect a third laptop into one port of SG-300 switch. It got an IP address automatically (I did not do any configure on SG-300, a new switch)
  3. laptop can ping successfully.
  4. laptop can ping, but cannot ping, which is behind SG-300 switch.

Hence, to make ping each other successfully, how to configure SG-300 switch?

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  • 2
    Are you sure that laptop can ping successfully (just to be sure it is not a typo)? If it can, then L2 and L3 connectivity appear to be ok and so should also be able to ping If not, then perhaps a host based firewall on is dropping the pings.
    – hertitu
    Oct 10, 2016 at 9:09
  • yes, can ping maybe firewall, let me check.
    – TJCLK
    Oct 10, 2016 at 9:37
  • correct, it is the laptop firewall issue.
    – TJCLK
    Oct 10, 2016 at 9:46
  • I tried another case (background information no change): laptop can only ping SG-300 switch if its IP address is set by DHCP instead of manual address (same address). Do you know what is the reason?
    – TJCLK
    Oct 10, 2016 at 9:52

2 Answers 2


(copying from the comments as it was confirmed to be the solution)

If can ping successfully then L2 and L3 connectivity appear to be ok and so should also be able to ping If not, then the most likely explanation is that a host-based firewall on is dropping the pings.


To ensure communication between IP address and both ip address belongs to different Vlans to ensure communication between different Vlans inter-Vlan need to be done , for doing inter-Vlan routing layer3 device is required . Where as cisco 2960 is layer2 device . Move both Vlans to Cisco SG300 switch hence this switch has layer3 capabilities inter-Vlan routing can be done in sg300 switch .. further connect Cisco 2960 switch trunk link allowing both Vlans passing through this link connecting access-list and SG300 switch .

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