Binding a /22 Subnet in Ubuntu 16 not working

I'm trying to add *secondary* subnet, a /22 in Ubuntu 16 but the IPs don't ping despite proper routing at the switch level. How do I properly bind the secondary /22 subnet (IPv4) and have these IPs ping?

I can ping locally, but not from external. Below commands didn't work.

root@server:~# iptables -A INPUT -p icmp --icmp-type echo-request -j ACCEPT
root@server:~# iptables -A OUTPUT -p icmp --icmp-type echo-reply -j ACCEPT

Routing at the Cisco switch level is fine too:

interface Vlan100
 description Server xxx
 ip address xxx.xxx.16.1 255.255.252.0 secondary
 ip address xxx.xxx.105.41 255.255.255.248

/etc/network/interfaces shows something like this...

    # This file describes the network interfaces available on your system
    # and how to activate them. For more information, see interfaces(5). source /etc/network/interfaces.d/*

    # The loopback network interface
    auto lo
    iface lo inet loopback

    # The primary network interface
    auto eno1
    iface eno1 inet static
        address xxx.xxx.105.42
        netmask 255.255.255.248
        network xxx.xxx.105.40
        broadcast xxx.xxx.105.47
        gateway xxx.xxx.105.41
        # dns-* options are implemented by the resolvconf package, if installed
        dns-nameservers 8.8.8.8 8.8.4.4
        dns-search mydomain.com

iface eno1 inet static
  address XXX.XXX.16.0/22
root@server:~# ifconfig |more
eno1      Link encap:Ethernet  HWaddr d4:be:d9:ed:fb:8a  
          inet addr:xxx.xxx.xxx.42  Bcast:xxx.xxx.xxx.47  Mask:255.255.255.248
          inet6 addr: fe80::d6be:d9ff:feed:fb8a/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:7386 errors:0 dropped:0 overruns:0 frame:0
          TX packets:457 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:478778 (478.7 KB)  TX bytes:467117 (467.1 KB)

eno1:0    Link encap:Ethernet  HWaddr d4:be:d9:ed:fb:8a  
          inet addr:xxx.xxx.16.1  Bcast:xxx.xxx.19.255  Mask:255.255.252.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1