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Load Balancing and redundancy (own public subnet)

Dear All,

See the snapshot i need to make Load Balancing and Redundancy for my network.  I am using Multi Homed BGP using my own 256 ip address public subnet.

1st Half i was advertised from ISP1

2nd Half i was advertised from ISP2.

My question is that by taking my own public ip i can make load balancing and redundancy (load balancing for incoming and outgoing traffic)?

-  I was try to browse Internet using 1st half of Ip address and using 2nd ISP router ip address Gateway, so i can't browse internet, any misconfigured from ISP or my side.

-  If i am sending traffic from ISP1 and return traffic is not coming from ISP2.

-  If i am sending traffic from ISP2 and retrun traffic is not coming from ISP1.

I need over all load balancing and redundancy for my incoming and outgoing traffic.

1 Accepted Solution

Accepted Solutions

Marwan ALshawi
VIP Alumni
VIP Alumni

Public ip addresses allocated from an ISP it can't be reach through another ISP if it's advertised through the ce customer router normally ISP put filtering and allow only the range they assigned to u to b advertised

If u have a public BGP u might b able to do it

Try to contact ur ISP and have a chat with them to confirm

Good luck

If helpful rate

Sent from Cisco Technical Support iPhone App

View solution in original post

5 Replies 5

George Horton
Level 1
Level 1

I would suggest that you have the switches multi connected to the firewalls as well, so that each firewall can talk to either of the ISP routers.  I would also suggest advertising the whole /24 as well as the /25's.

ISP1

     first half of subnet

     whole subnet

ISP2

     second half of subnet

     whole subnet

This would mean that if ISP1 went down, or had an issue traffic could come back via ISP2.

Hi George,

Many thanks for your reply, my question is that I was configured Multihoming BGP configuration and i am facing some problem like,

I was advertise 1st half of the subnet from ISP1 and second half subnet from ISP2.  I connected my laptop to and i assign one ip address from ISP1 side (1st Half subnet to laptop & ISP2 IP address as gateway) this time i am not accessing Internet and i am using wise versa so i cant browse Internet.

Can you suggest me how i can make load balancing and redundancy 100% as per my last attached daigram.

regards,

Marwan ALshawi
VIP Alumni
VIP Alumni

Public ip addresses allocated from an ISP it can't be reach through another ISP if it's advertised through the ce customer router normally ISP put filtering and allow only the range they assigned to u to b advertised

If u have a public BGP u might b able to do it

Try to contact ur ISP and have a chat with them to confirm

Good luck

If helpful rate

Sent from Cisco Technical Support iPhone App

Dear Marwan,

If i take public BGP (what mean public BGP, public autonomou only or any other) so i can used 100% load balancing and redundancy.  And Other thing is that if i send traffic from ISP1 and received from ISP2.

We have our own 254 Public Ip address.  1 to 128 advertised from ISP1 and 129 to 254 Advertised from ISP2.

Please let me now any document have explain about 100% load balancing and redundancy.

regards

hi

first can you see the route advertised from your side to IPS1 from the router connected to ISP 2 ?

are you using diffrent AS numbers form your side with each ISP ?

is the Public IP range assigned to you by one of those ISPs ?

with Public BGP ASN ( from IANA) your BGP AS will be seen in the internet AS path by all ISPs and if you want to influence path selection using AS path this can be easier as if you have AS given to you by your ISP this might be private and your ISP AS will overwrite it when advertised to the Public/other ISPs

also if you got your IP range from one ISP normally the other ISP might block it due to IPS polices and you need to request from them to allow this range to be advertised from you CE side

one more thing you need to consider advertising to the internet with diffrent ISP some times tricky interms of internal ploices within each ISP network it self

because they use some BGP community strings to change some BGP attributes of the route within the ISP itself thats why you need to check these options wiht each of the ISPs

by the way there is not 100% loadbalncing with routing it is relative only

if yo looking ot the level of LB then you need to consider some loadbalancing devices !

Good lcuk

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