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Cant ping next hop IP using switch as default gateway
Cant ping next hop IP using switch as default gateway
12-15-2014 10:54 PM
I have an S2500-48P with 3 VLANS on it. VLAN 1(IP 192.168.1.254/24), VLAN 2(IP 192.168.3.254/23), VLAN 3(IP 192.168.5.254/23). I am using the switch as the default gateway for all the clients Traffic is then NAT'ed on a cisco router with LAN IP 192.168.1.252. I se the default gateway of the switch to 192.168.1.252. When I do a show ip route I see the following
0.0.0.0 0.0.0.0 via 192.168.1.252
192.168.1.0/24 connected on VLAN 1
192.168.1.254/32 connected on VLAN 1
192.168.2.0/23 connected on VLAN 2
192.168.3.254/32 connected on VLAN 2
192.168.4.0/23 connected on VLAN 3
192.168.5.254/32 connected on VLAN 3
Client 1 (IP 192.168.1.251 subnet 255.255.255.0 DG 192.168.1.254)
Client 2 (IP 192.168.3.251 subnet 255.255.254.0 DG 192.168.3.254)
Client 3 (IP 192.168.5.251 subnet 255.255.254.0 DG 192.168.5.254)
Client 1 can pin the next hop (192.168.1.252) and can ping client 2 and 3.
Client 2 and 3 can ping each other and can ping VLAN 1 switch IP (192.168.1.254) but cant ping next hop (192.168.1.252).
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Re: Cant ping next hop IP using switch as default gateway
Re: Cant ping next hop IP using switch as default gateway
12-16-2014 01:28 AM
Hi Friend,
Can you share some more information ? such as,
1. L3 config of VLANs , "show ip interface brief"
2. NAT config. "show interface vlan <id>"
3. Routing table of the cisco router, "show ip route"
Please comeback with the above info, I will surely help you to fix the issue.
Venu Puduchery,
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Re: Cant ping next hop IP using switch as default gateway
Re: Cant ping next hop IP using switch as default gateway
12-16-2014 02:39 AM
I have had to add a few more vlans but the essentials are the same. Herewith the following
1) Show IP interface brief
Flags: S - Secondary IP address
Probe: U - Up, D - Down, U/O - Up & Own IP, N/A - Not Applicable
Interface IP Address / IP Netmask Admin Protocol Probe Flags
vlan 1 192.168.1.254 / 255.255.254.0 Up Up N/A
vlan 10 192.168.19.254 / 255.255.254.0 Up Up N/A
vlan 12 192.168.23.254 / 255.255.254.0 Up Up N/A
vlan 13 192.168.25.254 / 255.255.254.0 Up Up N/A
vlan 14 192.168.27.254 / 255.255.254.0 Up Up N/A
vlan 2 192.168.3.254 / 255.255.254.0 Up Up N/A
vlan 20 192.168.39.254 / 255.255.254.0 Up Up N/A
vlan 3 192.168.5.254 / 255.255.254.0 Up Up N/A
vlan 300 unassigned / unassigned Up Up N/A
vlan 5 192.168.9.254 / 255.255.254.0 Up Up N/A
vlan 7 192.168.13.254 / 255.255.254.0 Up Up N/A
vlan 8 192.168.15.254 / 255.255.254.0 Up Up N/A
vlan 9 192.168.17.254 / 255.255.254.0 Up Up N/A
mgmt unassigned / unassigned Up Down N/A
2 ) I am not doing any NAT on the switch.
3) Cisco config is as below
interface GigabitEthernet0/0
description To-LAN-network
ip address 192.168.1.252 255.255.0.0
ip nat inside
ip virtual-reassembly in
load-interval 30
duplex auto
speed auto
no cdp enable
!
interface GigabitEthernet0/1
description To-ISP-router
ip address 41.xxx.xx.xx 255.255.255.248
ip nat outside
ip virtual-reassembly in
load-interval 30
duplex auto
speed auto
no cdp enable
!
ip forward-protocol nd
!
no ip http server
no ip http secure-server
!
ip nat inside source list 1 interface GigabitEthernet0/1 overload
ip nat inside source static tcp 192.168.2.253 80 41.xxx.xx.xx 80 extendable
ip nat inside source static tcp 192.168.2.236 80 41.xxx.xx.xx 1236 extendable
ip nat inside source static tcp 192.168.2.237 80 41.xxx.xx.xx 1237 extendable
ip nat inside source static tcp 192.168.2.238 80 41.xxx.xx.xx 1238 extendable
ip nat inside source static tcp 192.168.2.239 80 41.xxx.xx.xx 1239 extendable
ip nat inside source static tcp 192.168.2.240 80 41.xxx.xx.xx 1240 extendable
ip nat inside source static tcp 192.168.2.241 80 41.xxx.xx.xx 1241 extendable
ip nat inside source static tcp 192.168.2.8 22 41.xxx.xx.xx 2222 extendable
ip nat inside source static tcp 192.168.2.253 8080 41.xxx.xx.xx 8080 extendable
ip nat inside source static tcp 192.168.1.250 8181 41.xxx.xx.xx 8181 extendable
ip nat inside source static tcp 192.168.1.250 22 41.xxx.xx.xx 8282 extendable
ip nat inside source static tcp 192.168.2.8 80 41.xxx.xx.xx 8888 extendable
ip nat inside source static tcp 192.168.2.8 10000 41.xxx.xx.xx 10000 extendable
ip route 0.0.0.0 0.0.0.0 41.190.46.49
!
access-list 1 permit 192.168.0.0 0.0.255.255
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Re: Cant ping next hop IP using switch as default gateway
Re: Cant ping next hop IP using switch as default gateway
12-16-2014 04:38 AM
HI,
As per the information given, Routing table and the VLAN interface info are not matching.
as per the VLAN interface :
VLAN 1 : 192.168.1.0 /23
VLAN 2 : 192.168.3.0 /23
VLAN 3 : 192.168.5.0 /23
As per the routing table of the switch :
VLAN 1 : 192.168.1.0 /24
VLAN 2 : 192.168.2.0 /23
VLAN 3 : 192.168.4.0 /23
Here my point is, why VLAN 1 subnet is populated as /24 in the routing table ? and summarised routes of VLAN 2 and 3 are showing different ?
if you made some changes after showing the routing table please share the current routing table
Please feel free to come back on this
Venu Puduchery,
[Is my post helped you ? Give Kudos :) ]
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Re: Cant ping next hop IP using switch as default gateway
Re: Cant ping next hop IP using switch as default gateway
12-24-2014 01:55 AM
Thanks for all the help. Turns out that the NAT router which is controller by the ISP didnt have the correct routes on it. SO got them to add the routes for the rest of the subnets and we are all up and running.
Thanks again for the help
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